cmake guru required so I can finish x265 Portfile

[davidfavor (David Favor)]

When building libx264, -install_name $PREFIX/lib/libx264.142.dylib is used when generating the dylib.

The x265 cmake project targets Linux, so there's no addition of this ld directive.

My question is this...

Let me know the best way to add this directive to the cmake project.

I'm using the MultiCoreWare code base.

hg clone ​https://bitbucket.org/multicoreware/x265 x265.hg

Thanks.