Better Javascirpt Minification

  - Tweaked UglifyJS settings
  - Running tests on minified version
Update README.md
Bugfix: Stop polling when poller is stopped

  - Added condition
  - Added a test case

Fixes #19
bumped version to 0.2.6
fixed returned type
tweaked docco build
Merge branch 'master' into gh-pages

Conflicts:
	backbone.poller.js
	backbone.poller.min.js
Updated annotated soucre code