[Profiler] Add a new profiler module to track GCHandle allocations

[Profiler] Add a new profiler module to track GCHandle allocations

This profiler was initially developed for Moonlight to diagnose and
fix issues where objects were never being GC'ed due to gchandles
being attached to objects and not freed. This profiler is just as
useful for other frameworks which rely on GCHandles to provide memory
management facilities such as gtk-sharp.

The aim of this profiler is to allow you to easily see how many instances
of each class are being kept alive by GCHandles and also the stacktrace
from where the GCHandle was allocated.

The profiler also tracks when instance delegates are passed to/from native
code as this can be a severe performance hit if it is done frequently.

Conflicts:

	mono/profiler/Makefile.am