#82 mingw compilation issues

[Michael]

I had some compilation issues when trying to compile with mingw all related to the Makefile, so I figured I'd mention them here:

1) A general make failed with undefined references to zlib functions, even though I had it installed/setup on my system. The solution for this was to move $(BASE_LDFLAGS) at the end of the respective command in the Makefile.

2) A make win failed with multiple definitions for some functions and missing references to other functions. The solution for this was to:

• change the line packager.o: qccguistuff.c qcc.h to packager.o: packager.c qcc.h in the Makefile
• add decomp.o as a compilation unit to WIN32GUI_OBJS in the Makefile

I also noticed that some header files didn't have include guards, but I guess thats not an issue as long as it compiles (more something that I preemptively do for my projects).

[eukara]

These should be fixed, as we went over those around the same time and I've since built many binaries on mingw for win32

[Xylemon]

Moved to https://github.com/fte-team/fteqw/issues/66