This patch improves the cmake bundling process:
- reworked bundle handling for OS X: only when installing resources are copied, otherwise
only the smallest bundle is built
- on OS X, the utility programs (tex2lyx) are now installed in the right location
- it removes some unneeded BUNDLE DESTINATION
- it provides a basic support for QT plugins inclusion
- it properly builds a disk image on OS X (only the background image is missing)
- it fixes the library paths for all executables (not only LyX)
- Use the COPYING file for cmake install license
