Added experimental (and optional) support for Qt5

git-svn-id: http://opensource.mlba-team.de/svn/xdispatch/trunk@552 9e4c620c-c391-4b63-a7fb-4924991ea895
Follow-Up to last commit: Added experimental (and optional) support for Qt5

git-svn-id: http://opensource.mlba-team.de/svn/xdispatch/trunk@553 9e4c620c-c391-4b63-a7fb-4924991ea895
No need to use a QWeakPointer in here, the QScopedPointer of the other data should be safe

git-svn-id: http://opensource.mlba-team.de/svn/xdispatch/trunk@554 9e4c620c-c391-4b63-a7fb-4924991ea895
Tested Qt5 on OS X, some fixes when using libcxx

git-svn-id: http://opensource.mlba-team.de/svn/xdispatch/trunk@555 9e4c620c-c391-4b63-a7fb-4924991ea895
Improved the libcxx compatibility tests

git-svn-id: http://opensource.mlba-team.de/svn/xdispatch/trunk@556 9e4c620c-c391-4b63-a7fb-4924991ea895