Kill meterpreter support for osx webcam/mic modules.

There is some bug (RM #8457) that I haven't been able to track down that causes the
osx call to run the event queue to just hang on latest OSX + Java/python
meterpreter. I tried rewriting these modules using OSX's new Media API,
but I run into the same problem. Until I find a solution, we should mark
these shell-only.