generalize tag-splitting option (#92)

- extend functionality to other booru sites:
  - http://behoimi.org/
  - https://konachan.com/
  - https://e621.net/
  - https://rule34.xxx/
  - https://safebooru.org/
  - https://yande.re/

gallery_dl/extractor/yandere.py

@@ -9,37 +9,13 @@
 """Extract images from https://yande.re/"""
 
 from . import booru
-from .. import text
 
 
 class YandereExtractor(booru.MoebooruPageMixin, booru.BooruExtractor):
     """Base class for yandere extractors"""
     category = "yandere"
     api_url = "https://yande.re/post.json"
-
-    def __init__(self, match):
-        super().__init__(match)
-        if self.config("tags", False):
-            self.prepare = self._categorize_tags
-
-    def _categorize_tags(self, image):
-        url = "https://yande.re/post/show/{}".format(image["id"])
-        page = self.request(url).text
-        taghtml = text.extract(page, '<ul id="tag-sidebar">', '</ul>')[0]
-
-        pos = 0
-        tags = {"artist": [], "copyright": [], "character": [],
-                "circle": [], "faults": [], "general": []}
-
-        while True:
-            tagtype, pos = text.extract(taghtml, "tag-type-", '"', pos)
-            if not tagtype:
-                break
-            tagname, pos = text.extract(taghtml, "?tags=", '"', pos)
-            tags[tagtype].append(text.unquote(tagname))
-
-        for key, value in tags.items():
-            image["tags_" + key] = " ".join(value)
+    post_url = "https://yande.re/post/show/{}"
 
 
 class YandereTagExtractor(booru.TagMixin, YandereExtractor):
@@ -69,8 +45,6 @@ class YanderePostExtractor(booru.PostMixin, YandereExtractor):
             "tags_artist": "sasaki_tamaru",
             "tags_circle": "softhouse_chara",
             "tags_copyright": "ouzoku",
-            "tags_character": str,
-            "tags_faults": str,
             "tags_general": str,
         },
     })]