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...

Created JsDuck::HTML class which implements #strip_tags and also proxies
CGI methods #escapeHTML and #unescapeHTML for more unified interface.

Some titles contain links, resulting in links-inside-links which is of
no good.

In 1.9 the Hash#select method returns a Hash, but in 1.8 it returns an
array which can be converted to a hash using Hash[] (when passed a hash
it will just pass through) - so now the code will produce a hash in both
1.8 and 1.9.

Created a #saveNew method directly on model, which ensures that
when we add the comment, we automatically mark it as read for
moderators.

Mongoose documentation doesn't list such parameter, and in comments app
code it's nowhere used.

This way it's also similar to ExtJS docs where there is a extjs-build/
dir.

Expanding when more lines added.

Additionally remove enterMode config, which is no more supported,
but the existance of which doesn't seem to make a difference.