Reviewed by Maciej.

        Add QT build slave to Buildbot.

        * BuildSlaveSupport/build.webkit.org-config/webkit/builders.py: Add QT build slave, fix existing errors.
        * BuildSlaveSupport/build.webkit.org-config/webkit/factories.py: Add QT build factory.
        * BuildSlaveSupport/build.webkit.org-config/webkit/status.py: Disable forcing of builds via web interface to prevent spamming.  Use the IRC bot in #webkit-build instead.
        * BuildSlaveSupport/build.webkit.org-config/webkit/steps.py: Add CMake build step.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@16704 268f45cc-cd09-0410-ab3c-d52691b4dbfc