linked physics overrides should allow property changes (make local)

My workflow makes it optimal to get optimal physics settings in a library object (soft-body, particle system (hair or emitter), cloth, etc) and then have the ability to tweak/change properties after link/override.

The most important (and perhaps obvious) of these is the cache bake end-time. But one might also like to change Hair or Soft-Body Field Weights.

One discussion can be found here in bug reports.

It should at least be possible to make-local the physics modifier, so that one can make changes.