pkg.m4: Add link test
Submitted by Elrond
Assigned to Tollef Fog Heen @tfheen
Description
I think, it would be helpful, if either PKG_CHECK_MODULES or a new macro would try to compile/link a simple program with the just detected flags to make sure, they really work.
This would catch trivial issues, like the .pc file existing, but the .a/.so not existing.