methodpool: also call native methods

methodpool: also call native methods

some comments:
(1) we need shared libs now, otherwise the binary too big (~24MB).
    please recompile from cabal (see README)
(2) as C doesn't allow '/', '(' and ')' as identifier names (unlike
    forth <3), we replace them with '_', in order to identify a
	(unique) native function. the pattern is as follows:
		class__methodname__methodsignature
(3) `loadNativeFunction' is quite hackisch now. I don't know if we
    get troubles with it at some point. we should consider:
		(3a) ask on stackoverflow
		(3b) patch this wtf stuff in ghc
		(3c) just determine addresses at compile-time.

	(3c) sucks, because you have to write much glue-code for every
	native method. but maybe we could solve it with some magic TH
	stuff (as suggested by hs_)