stdlib make crashes if it can't find png.

Bugzilla Link	1054
Created on	Mar 29, 2013 20:13
Version	svn
OS	Linux
Architecture	PC

Extended Description

As of 2013-03-29, stdlib make crashes if the system it is running
on does not contain PNG, or if make can't find ping.h.
Which, in my case, it can't.
pngtools was installed by Ubuntu "apt-get install pngtools".
Copying png.h into /usr/include does not help things out,
so as a workaround, it is useless.