Added javadoc and optional parameters for Polling. Modified javadoc for
PlurkTop.
Added javadoc for Profile.
Added javadoc for Realtime.
Added javadoc for Responses.
Added javadoc for Users.
Fix javadoc of PlurkTop.
Fixed javadoc of Polling.
Merge remote-tracking branch 'origin/OAuth_APIs'
Merge remote-tracking branch 'qrtt1/master'
Merge pull request #6 from askeing/master

Added some Javadoc for APIs.