(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/extensions/ext-server_moinsave.js

@@ -1,5 +1,4 @@
-/* eslint-disable no-var */
-/* globals svgEditor, svgedit, svgCanvas, canvg, $, top */
+/* globals jQuery, svgEditor, svgedit, svgCanvas, canvg */
 /*
  * ext-server_moinsave.js
  *
@@ -13,32 +12,32 @@
  */
 
 svgEditor.addExtension('server_opensave', {
-  callback: function () {
-    'use strict';
-    var Utils = svgedit.utilities;
-    var saveSvgAction = '/+modify';
+  callback () {
+    const $ = jQuery;
+    const Utils = svgedit.utilities;
+    const saveSvgAction = '/+modify';
 
     // Create upload target (hidden iframe)
-    /* var target = */ $('<iframe name="output_frame" src="#"/>').hide().appendTo('body');
+    /* const target = */ $('<iframe name="output_frame" src="#"/>').hide().appendTo('body');
 
     svgEditor.setCustomHandlers({
-      save: function (win, data) {
-        var svg = '<?xml version="1.0"?>\n' + data;
-        var qstr = $.param.querystring();
-        var name = qstr.substr(9).split('/+get/')[1];
-        var svgData = Utils.encode64(svg);
+      save (win, data) {
+        const svg = '<?xml version="1.0"?>\n' + data;
+        const qstr = $.param.querystring();
+        const name = qstr.substr(9).split('/+get/')[1];
+        const svgData = Utils.encode64(svg);
         if (!$('#export_canvas').length) {
           $('<canvas>', {id: 'export_canvas'}).hide().appendTo('body');
         }
-        var c = $('#export_canvas')[0];
+        const c = $('#export_canvas')[0];
         c.width = svgCanvas.contentW;
         c.height = svgCanvas.contentH;
         Utils.buildCanvgCallback(function () {
-          canvg(c, svg, {renderCallback: function () {
-            var datauri = c.toDataURL('image/png');
-            // var uiStrings = svgEditor.uiStrings;
-            var pngData = Utils.encode64(datauri); // Brett: This encoding seems unnecessary
-            /* var form = */ $('<form>').attr({
+          canvg(c, svg, {renderCallback () {
+            const datauri = c.toDataURL('image/png');
+            // const {uiStrings} = svgEditor;
+            const pngData = Utils.encode64(datauri); // Brett: This encoding seems unnecessary
+            /* const form = */ $('<form>').attr({
               method: 'post',
               action: saveSvgAction + '/' + name,
               target: 'output_frame'