update package curl
update package libpng
package jpeg: fix missing stdio.h for FILE
update package libmng
package qtimageformats: libmng 2 compatibility
package qt: libmng 2 compatibility
package poppler: use lcms 2

Now that Qt uses libmng 2 which uses lcms 2, we should too.
package poppler: fix building poppler Qt 4 libraries

Poppler doesn't use qmake, so we resort to fixing the PATH so moc
can be found by the configure script.
package graphicsmagick: use lcms 2