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/src/JLBFont.cpp

@@ -222,7 +222,7 @@ float JLBFont::GetStringWidth(const char *string) const
     {
       ch = *p - 32;
       p++;
-      if (ch < 0) continue;
+      //if (ch < 0) continue; //TODO useless test per compiler's message, char always positive, bug needs fixing here
       len += mCharWidth[ch+mBase] + mTracking;
     }
   len -= mTracking;