[Freetype] memory management?

[graham]

Hi.  I'm wondering just how and when FreeType frees up the various
bits of memory that it allocates.  For instance, let's say I want to
implement my own caching scheme (since I process the bitmaps a little
bit before I use them).  So I want to be able to tell FreeType when
I'm done with stuff so it doesn't accumulate in ram, for instance. 
Any hints are good.  Thanks!

- Graham