Committing Nico's change about build system improvements for LAPACK

Committing Nico's change about build system improvements for LAPACK

"One of the improvements with the patches is that SOVERSION and VERSION are now properly set and the proper symlinks are created:
```
liblapack.so -> liblapack.so.3
liblapack.so.3 -> liblapack.so.3.5.0
liblapack.so.3.5.0
```
Since BLAS is shipped with LAPACK and no separate version number is given for BLAS, I applied the same there, too."

Tested on Julie's Mac

TO DO: To test under Windows
====

Updated OSX RPATH settings
In response to CMake 3.0 generating warnings regarding policy CMP0042,
the OSX RPATH settings have been updated per recommendations found
in the CMake Wiki:
  http://www.cmake.org/Wiki/CMake_RPATH_handling#Mac_OS_X_and_the_RPATH