Bug#395000: libgnatprj-dev: should Depend on libgnatvsn-dev
Since libgnatprj4.1 depends on libgnatvsn4.1, libgnatprj-dev should also
depend on libgnatvsn-dev. Moreover,
/usr/share/ada/adainclude/gnatprj.gpr should "with" libgnatvsn.gpr.
Failing that, all programs that build-depend on libgnatprj-dev must also
build-depend explicitly on libgnatvsn-dev, and their project files must
"with" gnatvsn.gpr explicitly rather than implicitly.