added button to access new modal for editor config
added new editor config modal
added aceConfig to user schema
save editor config to database
apply config to editor
including i18n support for new editor config and minor styling changes
removed unnecessary comment
Merge pull request #545 from dkundel/master

Implemented editor config to allow Vim & Emacs key bindings as proposed in #99
Fix for if aceConfig doesn't exist yet.
Added configuring of behaviors to the editor config.
Propagated new editor i18n tags.
Fixes issue where panning occurs upon mouse scroll at max/min zoom
Enables drag-panning for editor and region chooser
Added random session pair choosing

Due to a bug I cannot test this immediately
Put back the sort for the leaderboard handler.
Made editing thangs in the level editor not so slow by avoiding calling level.serialize.
Merge branch 'master' of https://github.com/codecombat/codecombat
Fixed random sessions fetching
Removed defaults on schema for ladder-related things
Hotfix for #550