Added detection of gtk2/gtk3 GUI libraries required by Alien::wxWidgets. Added gtk2/gtk3 include paths, so we may call gtk2/3 API directly if needed for some workaround.
Added detection of gtk2/gtk3 GUI libraries required by Alien::wxWidgets. Added gtk2/gtk3 include paths, so we may call gtk2/3 API directly if needed for some workaround.