quoting fixes

- allow bbcode quotes to be nested
- don't allow the '=' to be omitted from quotes
- fix some css that made assumptions about nested quotes

app/assets/javascripts/discourse/dialects/bbcode_dialect.js

@@ -105,6 +105,7 @@ replaceBBCodeParams("size", function(param, contents) {
 Discourse.Dialect.replaceBlock({
   start: /(\[code\])([\s\S]*)/igm,
   stop: '[/code]',
+  rawContents: true,
 
   emitter: function(blockContents) {
     return ['p', ['pre'].concat(blockContents.join("\n"))];