update elements and fix some bugs

lib/src/prism/components/prism-wiki.js

 Prism.languages.wiki = Prism.languages.extend('markup', {
         'block-comment': {
                 pattern: /(^|[^\\])\/\*[\w\W]*?\*\//,
                 lookbehind: true,
                 alias: 'comment'
         },
         'heading': {
                 pattern: /^(=+).+?\1/m,
                 inside: {
                         'punctuation': /^=+|=+$/,
                         'important': /.+/
                 }
         },
         'emphasis': {
-                pattern: /('{2,4}).+?\1/,
+                // TODO Multi-line
+                pattern: /('{2,5}).+?\1/,
                 inside: {
                         'bold italic': {
-                                pattern: /('''').+?(?=\1)/,
+                                pattern: /(''''').+?(?=\1)/,
                                 lookbehind: true
                         },
                         'bold': {
-                                pattern: /(''').+?(?=\1)/,
+                                pattern: /(''')[^'](?:.*?[^'])?(?=\1)/,
                                 lookbehind: true
                         },
                         'italic': {
-                                pattern: /('').+?(?=\1)/,
+                                pattern: /('')[^'](?:.*?[^'])?(?=\1)/,
                                 lookbehind: true
                         },
                         'punctuation': /^''+|''+$/
                 }
         },
         'hr': {
                 pattern: /^-{4,}/m,
                 alias: 'punctuation'
         },
         'url': [
-                /ISBN +(?:97[89][ -]?)?(?:\d[ -]?){9}[\dx]\b/i,
-                /(?:RFC|PMID) +\d+/,
-                /\[\[.+?\]\]/,
-                /\[.+?\]/
+                /ISBN +(?:97[89][ -]?)?(?:\d[ -]?){9}[\dx]\b|(?:RFC|PMID) +\d+/i,
+                /\[\[.+?\]\]|\[.+?\]/
         ],
         'variable': [
                 /__[A-Z]+__/,
+                // FIXME Nested structures should be handled
+                // {{formatnum:{{#expr:{{{3}}}}}}}
                 /\{{3}.+?\}{3}/,
                 /\{\{.+?}}/
         ],
         'symbol': [
                 /^#redirect/im,
                 /~{3,5}/
         ],
         // Handle table attrs:
         // {|
         // ! style="text-align:left;"| Item
@@ skipping 17 matching lines @@
         'nowiki': {
                 pattern: /<(nowiki|pre|source)\b[\w\W]*?>[\w\W]*?<\/\1>/i,
                 inside: {
                         'tag': {
                                 pattern: /<(?:nowiki|pre|source)\b[\w\W]*?>|<\/(?:nowiki|pre|source)>/i,
                                 inside: Prism.languages.markup['tag'].inside
                         }
                 }
         }
 });