Fix window caption disappereance in Linux
After commit 05bb5efca7 on Linux caption of main window reinitializing
to empty caption after switching from/to OpenGL.
This commit fixes that.
Show git revision via -DOPENXCOM_VERSION_GIT definition during
compilation.
Now we can set current git revision to version.h in commandline. It
works on CMake buildsystem, but you can use old Makefile with
make -DOPENXCOM_VERSION_GIT="some-revision"
Merge pull request #831 from winterheart/linux-window-caption-fix

Fix window caption disappereance in Linux
Merge pull request #832 from winterheart/show-git-revisions-in-game

Show git revision via -DOPENXCOM_VERSION_GIT definition during
only allow fully loaded tanks on craft
replace magic number with static const
add combobox to testState
give windows a thin border
use thin borders on combobox windows