Some preparation work for new platform support.

- Added a "PSP" compile-time define to clean up some compile time checks (replaced !WIN32 && !LINUX && !IOS with PSP) 
-- Wil, I am aware that this is redundant with the PSPENV variable you introduced recently, I think we can clean that up easily
-- This looks like lots of changes, but most of the time I just moved some blocks here and there
-- tested on VC 2010, PSP, and a bit of NDK
-- I might have broken maemo, iOS, or Linux compilation, can you guys check?
- Fixed some warnings reported by NDK
- NDK still does not compile because recent boost additions (mutex, etc...) are apparently not supported

JGE/Makefile

@@ -83,7 +83,7 @@ PSPDIR = $(shell psp-config --psp-prefix)
 OBJS = $(GENERIC_OBJS) $(PSP_OBJS)
 TARGET_HGE = libhgetools.a
 INCDIR = include/psp include/psp/freetype2 ../Boost
-CXXFLAGS += -O2 -G0 -DPSPENV
+CXXFLAGS += -O2 -G0 -DPSPENV -DPSP
 LIBDIR = lib/psp
 endif
 ifeq ($(TARGET_ARCHITECTURE),linux)