Encapsulate the checkboxes completely inside commentindex view, which
does the saving of checkbox states completely within itself, only
firering settingChange event for the controller to listen on.

No need to use cookies, we already have Docs.Settings class that uses
localStorage and is meant just for that - storing various settings.

Add #setMasked method to comments view and use that for
masking/unmasking.

Also rename #recentcomments-container to #comment-index-container for
consistency.

And remove absolute positioning from comment controls that's no more
needed.

Also remove check for commentMeta.reads - copy paste error.

Masking recent comments while loading, and remembering of filters
of recent comments.

Recent comments page now has two checkboxes:

  - hide read
  - sort by score

Not an efficient implementation, but should be good enough as only
moderators use the feature.

Loading the recent comments page caused a crash when there were no
comments.

Add Windows platform.

Without this the inline examples won't work as expected.

Running `bundle install` should now use the .lock file, and ensure
a more similar environment on every development machine.

Previously when singleton happened to be component, the component icon
was shown.

Using Ext.Element#on to attach load event handler to iframe element.
Assigning handler directly to iframe.onload didn't work in IE8.

I'm sure it also fixes the same problem in IE7 (at least it does so in
IE7-mode of IE8), and the fix itself is just applying the right way of
doing things.

This was used for tasks that are now built into JSDuck itself.

The hight now gets set to the right size the first time the editor is
activated.

Same thing as with comments editor - CodeMirror-scroll height defaults
to 300px which we override with 'auto'.

Looks like the upgraded CodeMirror handles itself much better and
so many forced refreshes aren't no more needed.

The previously used vbox layout caused some strange problems when
selecting text or typing to CodeMirror editor - the whole panel
shifted out of view towards left.

Remove need to call #initScrolling explicitly from all the initComponent
methods of classes that use this mixin.  Instead inject the call into
initComponent of those classes at creation time.

Re-implement the old behavior.

The Scrolling mixin now takes care of all this.

Refactor common scrolling methods into a mixin class that's used in both
class overview and guides container.

A regression caused by changing the guide container into panel.

Removed click handlers for guide - these simply didn't do anything
useful - the first one saved incorrect scroll state and the next one was
never triggered.  Planning to fix that in the commits to follow...