Added GooglePlus iOS SDK
Adjusted project settings for Google Plus.
Added SHKGooglePlus.h/.m
Added basic features for Google Plus
Finished the Google Plus URL/Text sharing.
Added Google Plus settings to the Demo App.
Corrected the implementation for Google Plus.
Handled Google Plus callbacks.
Added instructions in SHKGooglePlus.h.
Fixed some errors for SHKGooglePlus
Merge remote-tracking branch 'upstream/master'

Conflicts:
	ShareKit.xcodeproj/project.pbxproj
Rename the title "Google Plus" to "Google+"
Merge branch 'master' into googlePlus

Conflicts:
	ShareKit.xcodeproj/project.pbxproj
Merge commit '06ea747c50cc2c20521e7b38da8f2e9d59c46da4' into googlePlus
removed Google+ graphics and libGooglePlus.a from project, it is not needed