#3 configure.ac/Makefile.am improvements

[Hanno Böck]

Attached patch will
a) Remove reference to empty freegetopt dir
b) switch from pkg-config calls to proper autotools usage

especially b) is important, because else compilation of pngnq fails when using a linker with --as-needed enabled (this causes only really neccessary libraries/objects to be linked in, but that only works if the libs are passed to the linker in the correct order).

Please apply, patch is from Kacper Kowalik in this Gentoo Bug:
https://bugs.gentoo.org/show_bug.cgi?id=301002

[Hanno Böck]

pngnq-1.0-as-needed.patch