Bug#810183: cups: Please update dependency on libpng-dev

[tobi@debian.org]

Package: cups
Severity: important
User: libpng@packages.debian.org
Usertags: libpng16-transition

Dear cups maintainers,

Currently we are preparing the transition of libpng1.2 to libpng1.6.
The transition bug is #650601.

A rebuild of all packages depending on libpng-dev and
libpng(3,12,12-0)-dev has been done. The result with buildlogs can be
found here: https://libpng.sviech.de/

cups builds fine with libpng16, you can see the buildlog here:
https://libpng.sviech.de/cups.build

Howver, cups (build-)depends an versioned development package
libpng12-dev. Please update your (build-)depends to libpng-dev to
help in the transition.

This bug will become RC as soon as the transition starts, as it is
planned to remove libpng12. 

Thanks!
-- 
tobi