BundleUtilities: Check install_name_tool has -delete_rpath

Otherwise it will fail with Xcode 3.x on 10.5 which has no -delete_rpath option
for install_name_tool command, that was first introduced in 10.6 SDK, even that
10.5 supports LC_RPATH and @rpath.
Merge topic 'fix-OSX-bundle-rpaths-and-Qt5' into next

ecbd93b7 BundleUtilities: Check install_name_tool has -delete_rpath