Changed "global" endpoint to "common" endpoint to fix breaking change. Updated appid for sample app.
Merge branch 'v4.3' of https://github.com/DotNetOpenAuth/DotNetOpenAuth into v4.3

Conflicts:
	samples/OAuthClient/Web.config
Fixed Style Warnings
Merge pull request #281.

I rewrote history for the pull request in order to fix the commit author name.