Fixes for MXE cross-compile
Merge pull request #371 from mpetroff/mingw32-fixes

Fixes for MXE cross-compile
rename config.h to fontforge-config.h; clean configure-fontforge.h
include fontforge-config.h in fontforge.h, for those linking fontforge
clean code with GCC warning
Merge pull request #370 from JoesCat/master

This needs to wait for libuninamelist to be updated first....
Merge pull request #375 from coolwanglu/clean_warning

clean code with GCC warning
Merge pull request #374 from coolwanglu/rename_config

rename config.h to fontforge-config.h; clean configure-fontforge.h
Get stamper.c to build with fontforge-config.h (see previous commit).