simplify libpng detection - use libpng-config unless told otherwise.
commit917ba8b28ed925eccafefcb5a26d15087ee6ef35
authorNicJA <NicJA@fb15a70f-31f2-0310-bbcc-cdcc74a49acc>
Fri, 1 Apr 2016 22:02:23 +0000 (1 22:02 +0000)
committerNicJA <NicJA@fb15a70f-31f2-0310-bbcc-cdcc74a49acc>
Fri, 1 Apr 2016 22:02:23 +0000 (1 22:02 +0000)
treecd055d38fb413822658fe437ad3d7e0c906de349
parente8f711d9c36aa80f3151659a74813f7eed03b7c0
simplify libpng detection - use libpng-config unless told otherwise.

git-svn-id: https://svn.aros.org/svn/aros/trunk/AROS@52498 fb15a70f-31f2-0310-bbcc-cdcc74a49acc
configure
configure.in