Mistakenly pushed half-finished gem to RubyGems.
Deleted it from there, but RubyGems doesn't allow pushing a
previously pushed version up again.

The main repo is now moved to senchalabs.

Updated gemfile and documentation.

Now we have reached feature-parity with ext-doc.

Just ext-doc does it.

Updated README changelog also.

Explained in README that unlike with ext-doc constructor documentation
inherited like documentation for any method.

I really don't like to pollute every single file of JsDuck with
GPL license header as the GNU guys suggest.  So I just include it
into the main jsduck.rb file.  No harm done, I hope.

Plus some re-arrangements in README.

Plus some ExtJS strangenesses in use of @member.