(INCOMPLETE: ES6 Module conversion and linting)

- Breaking change: Require `new` with `EmbeddedSVGEdit` (allows us to use `class` internally)
- Breaking change: If `svgcanvas.setUiStrings` must now be called if not using editor in order
    to get strings (for sake of i18n) (and if using path.js alone, must also have its `setUiStrings` called)
- Breaking change (ext-overview-window): Avoid global `overviewWindowGlobals`
- Breaking change (ext-imagelib): Change to object-based encoding for namespacing of
    messages (though keep stringifying/parsing ourselves until we remove IE9 support)
- Breaking change: Rename `jquery.js` to `jquery.min.js`
- Breaking change: Remove `scoped` attribute from `style`; it is now deprecated and
    obsolete; also move to head (after other stylesheets)
- Enhancement: Make SpinButton plugin independent of SVGEdit via
    generic state object for tool_scale
- Enhancement: Remove now unused Python l10n scripts (#238)
- Enhancement: ES6 Modules (including jQuery plugins but not jQuery)
- Enhancement: Further JSDoc (incomplete)
- Enhancement (Optimization): Compress images using imageoptim (and add
    npm script) (per #215)
- Fix: i18nize path.js strings and canvas notifications
- Fix: Attempt i18n for ext-markers
- Refactoring (ext-storage): Move locale info to own file imported by the extension (toward modularity; still should be split into separate files by language and *dynamically* imported, but we'll wait for better `import` support to refactor this)
- Refactoring: For imagelib, add local jQuery copy (using old 1.4.4 as had
    been using from server)
- Refactoring: For MathJax, add local copy (using old 2.3 as had been using from
    server); server had not been working
- Refactoring: Remove `use strict` (implicit in modules)
- Refactoring: Remove trailing whitespace, fix some code within comments
- Refactoring: Expect `jQuery` global rather than `$` for better modularity
    (also to adapt line later once available via `import`)
- Refactoring: Prefer `const` (and then `let`)
- Refactoring: Add block scope keywords closer to first block in which they appear
- Refactoring: Use ES6 `class`
- Refactoring `$.isArray` -> `Array.isArray` and avoid some other jQuery core methods
    with simple VanillaJS replacements
- Refactoring: Use abbreviated object property syntax
- Refactoring: Object destructuring
- Refactoring: Remove `uiStrings` contents in svg-editor.js (obtains from locale)
- Refactoring: Add favicon to embedded API file
- Refactoring: Use arrow functions for brief functions (incomplete)
- Refactoring: Use `Array.prototype.includes`/`String.prototype.includes`;
    `String.prototype.startsWith`, `String.prototype.trim`
- Refactoring: Remove now unnecessary svgutils do/while resetting of variables
- Refactoring: Use shorthand methods for object literals (avoid ": function")
- Refactoring: Avoid quoting object property keys where unnecessary
- Refactoring: Just do truthy/falsey check for lengths in place of comparison to 0
- Refactoring (Testing): Avoid jQuery usage within most test files (defer script,
    also in preparation for future switch to ES6 modules for tests)
- Refactoring: Make jpicker variable declaration indent bearable
- Refactoring (Linting): Finish svgcanvas.js
- Docs: Mention in comment no longer an entry file as before
- Docs: Migrate old config, extensions, and FAQ docs
- Licensing: Indicate MIT is license type of rgbcolor; rename/add license file name for
    jgraduate and screencast to reflect type (Apache 2.0); rename file to reflect it
    contains license information (of type MIT) for Raphael icons

editor/embedapi-dom.js

@@ -1,21 +1,21 @@
-/* eslint-disable no-var */
-/* globals $, EmbeddedSVGEdit */
-var initEmbed; // eslint-disable-line no-unused-vars
+/* globals jQuery */
+import EmbeddedSVGEdit from './embedapi.js';
+const $ = jQuery;
 
-// Todo: Get rid of frame.contentWindow dependencies so can be more easily adjusted to work cross-domain
+// Todo: Add iframe load listener
+var initEmbed;
+
+// Todo: Get rid of frame.contentWindow dependencies so can be more
+//        easily adjusted to work cross-domain
 
 $(function () {
-  'use strict';
-
-  var svgCanvas = null;
-  var frame;
+  let svgCanvas = null;
 
   initEmbed = function () {
-    var doc, mainButton;
     svgCanvas = new EmbeddedSVGEdit(frame);
     // Hide main button, as we will be controlling new, load, save, etc. from the host document
-    doc = frame.contentDocument || frame.contentWindow.document;
-    mainButton = doc.getElementById('main_button');
+    const doc = frame.contentDocument || frame.contentWindow.document;
+    const mainButton = doc.getElementById('main_button');
     mainButton.style.display = 'none';
   };
 
@@ -28,7 +28,7 @@ $(function () {
   }
 
   function loadSvg () {
-    var svgexample = '<svg width="640" height="480" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g><title>Layer 1</title><rect stroke-width="5" stroke="#000000" fill="#FF0000" id="svg_1" height="35" width="51" y="35" x="32"/><ellipse ry="15" rx="24" stroke-width="5" stroke="#000000" fill="#0000ff" id="svg_2" cy="60" cx="66"/></g></svg>';
+    const svgexample = '<svg width="640" height="480" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g><title>Layer 1</title><rect stroke-width="5" stroke="#000000" fill="#FF0000" id="svg_1" height="35" width="51" y="35" x="32"/><ellipse ry="15" rx="24" stroke-width="5" stroke="#000000" fill="#0000ff" id="svg_2" cy="60" cx="66"/></g></svg>';
     svgCanvas.setSvgString(svgexample);
   }
 
@@ -37,9 +37,9 @@ $(function () {
   }
 
   function exportPNG () {
-    var str = frame.contentWindow.svgEditor.uiStrings.notification.loadingImage;
+    const str = frame.contentWindow.svgEditor.uiStrings.notification.loadingImage;
 
-    var exportWindow = window.open(
+    const exportWindow = window.open(
       'data:text/html;charset=utf-8,' + encodeURIComponent('<title>' + str + '</title><h1>' + str + '</h1>'),
       'svg-edit-exportWindow'
     );
@@ -47,7 +47,7 @@ $(function () {
   }
 
   function exportPDF () {
-    var str = frame.contentWindow.svgEditor.uiStrings.notification.loadingImage;
+    const str = frame.contentWindow.svgEditor.uiStrings.notification.loadingImage;
 
     /**
     // If you want to handle the PDF blob yourself, do as follows
@@ -58,7 +58,7 @@ $(function () {
     return;
     */
 
-    var exportWindow = window.open(
+    const exportWindow = window.open(
       'data:text/html;charset=utf-8,' + encodeURIComponent('<title>' + str + '</title><h1>' + str + '</h1>'),
       'svg-edit-exportWindow'
     );
@@ -76,5 +76,5 @@ $(function () {
       '" width="900px" height="600px" id="svgedit" onload="initEmbed();"></iframe>'
     )
   );
-  frame = document.getElementById('svgedit');
+  const frame = document.getElementById('svgedit');
 });