preconfig.sh: don't require ICU on OSX

This isn't needed for the full build, only QtWebKit which has it's own ways of finding the system ICU.
Merge pull request #1 from mikemcquaid/patch-1

preconfig.sh: don't require ICU on OSX
Update to latest Qt 5.3 branches.
Merge branch 'kdab-qt5' into javabindings

Conflicts:
	app/app.pro