adding Phenom[Internal]Utils.c/.h
These are new files to help improve the modularity of coding in lalsimulation. In particular for phenom waveforms.
src/LALSimIMRPhenomInternalUtils.c/.h
are designed so that you can include the .h file in any C code in lalsimulation and be able to use the functions defined in that file. However, these functions are not SWIG wrapped.
src/LALSimIMRPhenomUtils.c/.h
are designed so that any XLAL SWIG wrapped functions are defined here. In particular so that you can also call the functions defined in here from python