Move status bar code out of EditorManager into a new module. Keeps
EditorManager tightly focused on maintaining the set of Editors and gives
the status bar code room to grow for future UI additions.

This removes EditorManager._init() and the manual calls to it from unit
tests, which seem unnecessary. EditorStatusBar._init() is still called on
htmlReady - just not manually called by any unit tests.

Also, change the status bar code to use active editor more consistently
(used to use focused editor sometimes).
Actually removing the statusbar-related require() calls from EditorManager
now that the code that uses them has been moved elsewhere. Breaks circular
dependency between StatusBar & EditorManager.
Fix bug where JSLint indicator was always gray. StatusBar's init was a bit
intertangled with its main client (previously EditorManager, now
EditorStatusBar), which meant other clients can't guarantee the status bar
is initialized before their own htmlReady() handler merely by require()ing
StatusBar. Fixed by having StatusBar initialize itself. This makes it a bit
less generic... but only a bit - it was already not reusable since it's all
singleton APIs and its HTML contains hardcoded support for EditorStatusBar's
UI.

Minor other fixes: log console errors when StatusBar APIs are called too
early (instead of silently dropping on floor); fix copyright date; remove
unneeded JSLint globals.
Merge remote-tracking branch 'origin/master' into pflynn/separate-statusbar

* origin/master:
  Move the command and string to the right place
  update inner mode detection for codemirror v3
  remove red bg color when deleting search arg
  Don't clear Find results counter if it's about to get overwritten by running a new search query. I think this was a mistake from a bad merge/rebase with master.
  Update CodeMirror SHA to latest upstream master
  Changes after review
  Updated by ALF automation.
  Fix bug #330 (Calling FileIndexManager.getFileInfoList() while another such call is already in progress fails) - keep track of existing index-sync promise so we can just wait on it instead of failing.
  Adding the CodeMirror built-in Auto Close Brackets addon
  Show number of search results in Find bar while typing
  Updated by ALF automation.

Conflicts:
	src/editor/EditorManager.js
Merge pull request #3061 from adobe/pflynn/separate-statusbar

Cleanup: Move status bar code out of EditorManager into a new module