[ITK] Pull requests on github

[Michka Popoff]

Hi

would it be possible to close the pull request feature on the ITK github accounts ?
This will prevent double posting patches (and asking people to move their patch to gerrit). They should directly post on gerrit.

Maybe we would need to add one sentence in the README, people on github are accustomed to use pull requests,
so they will maybe wonder where to post their patches ? (And maybe also a link to the JIRA bug tracker).

Thanks

Michka