Mac OS X: Add back into installset LibreOffice.app/Contents/MacOS/ files

...that were erroneously removed with 6492c8576e0393f7ee548cd938e84c80e8d37127
"Make the 'Mac-like' or 'canonical' app bundle structure always used on OS X":

* gengal script (ultimately calling gengal.bin); this script still needs
  adaption to the new LibreOffice.app layout, though!

* python script (ultimately calling Python.app)

* unoinfo script

* unopkg symlink to unopkg.bin (which could be dropped for Mac by renaming
  unopkg.bin to just unopkg, similarly to soffice/soffice.bin)

Change-Id: Ic3eb340a183388939b1c812faf7fb509c9f53a8a