Previously H5 and H6 weren't styled at all, resulting them looking
like plain text.

Also print out message in verbose mode about the auto-detected
config file, so reading it happens with less magic.

Fixes #402

But instead of standard RKelly gem, use our own rkelly-remix fork.

Previously all property keys were treated as being
identifiers - now we correctly detect if they're
strings or numbers.

RKelly chokes when it sees that.

Causes problems with RKelly which chokes when it sees a reserved
word like that inside a property chain.

Ext 1.1 source happened to contained code like:

    /**
     * @param {String} (optional)
     */

which brought JSDuck crashing down.

The Js::Associator expects all nodes to have "range".

Inside RKellyParser:

- Invoke RKelly.
- Adapt its output with RKellyAdapter
- Set the correct range for root node.
- Pass the adapated AST to Associator.

Change RKellyAdapter to:

- Create root "Program" node.
- Adapt the comment nodes inside this root node.
- Adjust the range end by one - so it matches the esprima way.
- Include line number to the adapter range.

Intending to use the same logic in RKellyParser.

In an attempt to replace Esprima with RKelly, I created an adapter
to convert the RKelly AST into Esprima AST.

The backwards-compatibility fix for code like:

    Here's the code example:<pre><code>
    alert("Blah");
    </code></pre>

was a bit too lose.  So tightened it up to only apply in case
where the <pre> or <pre><code> is at the end of line.

Fixes: #380

There was a conflict with one method looping over array while
other deleting items from it at the same time.

Fixes: #378

The existing code for skipping constructors had become outdated.

Instead the MemberTag class now has two helper methods:

- member_link - for rendering member name as a link.
- member_params - for rendering the params list.

Most of the complexity was really related to rendering the
method signature - all this logic is now in Tag::Method class.

Some leftover from old times - not needed at all.

Without this 1px shift some of the icons will be missing pixels from the
bottom.

Member icons are now defined in member tag classes.  There the
:icon field defines the icon file which is included to the docs
app resources and an appropriate CSS gets generated.

In Ruby 1.8 it happens that MemberTag is loaded twice and the
constants in it get redefined, and trigger a warning.