The move to LIBEXEC_PATH broke running the puppet from the packages on
Linux and OS X, because there it cannot find the platform plugin
anymore.
We need to add a qt.conf for it, and because Qt Creator.app/Contents/
Resources already contains the qt.conf for Qt Creator itself, the puppet
must also move to its own subdirectory on OS X.

Change-Id: I8e8cc48c49a01e10c7d7d3cc4c73020195cd5ca9
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>