Merge remote-tracking branch 'upstream/master' into achievements_progress

Conflicts:
	app/views/editor/level/LevelEditView.coffee
	server/levels/sessions/LevelSession.coffee
Refactored New Model Modal (from SearchView originally)
Added related achievements tab to level editor
Added user images
Fixed components w/out changes sometimes showing up in the save level modal.
Removed a bit for debugging.
Fixed ComponentDocsView's components collection overwriting data for other level editor data. Related to #1108.
Hiding the randomize button overlay until #1409 is handled.
Update ru.coffee
Made sure items equip themselves within the SpriteBoss, too.
Fixes for item equipping, Component saving, and terrain randomization wall snapping/overlap avoidance.
Fixed #1062. Added Item kind to level editor Thang filters.
Added a function for denormalizing levels, extending level thang components and configs with ones from thang types.
community page redesign
Merge branch 'master' of https://github.com/codecombat/codecombat
Table headers are now unhoverable
Removed editorMode.
Added new level 'QuickSort the Spiral'
Minor name fix
Extended the LevelLoader to load thang types and components dynamically for hero levels.