Fast and various

Global:

• [Added] support for brackets in tag names
• [Added] option in user settings for hiding disliked posts

Frontend:

• [Fixed] HTML validation
• [Fixed] better placement of auto-completion boxes
• [Fixed] removed some unused Javascript code
• [Fixed] simplified slow jQuery selectors
• [Fixed] some CSS problems with Chrome and Firefox
• [Fixed] some Markdown problems regarding <pre> tags
• [Fixed] tags in page title and tooltips are sorted
• [Changed] upgraded jQuery to 2.0.3
• [Changed] moved Javascript include statements from HEAD to footer
• [Changed] better looking SQL queries debug
• [Changed] help tab title from "help" to "general help"
• [Added] stylized Markdown quotes
• [Added] active section (browse, help, ...) indicator
• [Added] jQuery .map file (no more 404 when using developer tools)

Backend:

• [Added] support for MySQL
• [Changed] faster search by tag / comment / submit / favorites (useless nested joins
  replaced to entity prefetch). Side effect: searching for nonexistent tags,
  users etc yields informative errors instead of "no posts to show")
• [Changed] options section from sidebar in various pages rendered from within one file
• [Changed] removed RedBeanPHP dependancy
• [Changed] rewritten whole model layer
• [Changed] most of pages load 1.5 to 2x faster