- Removed the use of the environment variable PKG_CONFIG_LIBDIR
While building binaries the tool {i686,x86_64}-w64-mingw32-pkg-config
should be used to find out pkg-config information
The environment variable PKG_CONFIG already automatically points
to the right cross-compiler aware version of pkg-config when
the mingw{32,64}-pkg-config packages are installed
- Fixes compilation of mingw-gtk3 3.9.0 (GNOME BZ #699690)
- Automatically add R: mingw{32,64}-pkg-config tags when .pc files
are detected while building mingw packages