Improved previous XHR management

This fix prevents calls to abort() of previously finished AJAX requests to the server.
Merge pull request #280 from andresmoschini/documentation

Documentation
Merge pull request #281 from andresmoschini/frontpage-links

Frontpage links
Include full Epnuke.OAuth.Library sources
Open and migrate?
Little change to get twitter demo working
Add new empty demo project to test google
Fix a bug in Twitter demo
Allow signout in Twitter demo
Add basic authentication to Google demo
Add Google OAuth requests (it is not working)