32e497b Let's call them GTKCFLAGS, not G...

based on: http://github.com/torvalds/subsurface/commit/32e497b5744ef690e91b4a9f22a63109dde4c7df

compiled with: mingw 3.4.5

notes:
Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>