Upgrading to current upstream stable release
Also added license information to the SPKG.txt file.
Patching libpng to allow compilation of libfreetype-2.5.2
Fixed patching of libpng.
Merge branch 'pillow' into ticket/15561

PIL (curentl in master) doesn't compile with freetype 2.5.2. Pillow (currently
in branch u/ohanar/pillow in trac#15539, fixed) should. Hence merging it.
buid/deps : added a dependency of freetype on libpng in order to work
around a build-time race condition.
Trac #15561: freetype 2.3.5 is too old for some fonts of current systems.

The now-current freetype library has problems with newer fonts. This
forbids its uses in some applications on machines having system fonts
not supported by this version.

This was diagnosed on sage's R (see
[https://groups.google.com/forum/#!topic/sage-support/FnTEcpfg6wE this
thread]) by Volker Braun.

A stopgap measure is to upgrade freetype to a more forgiving version of
freetype, hence this ticket.

The current freetype tarball hits a snag in libpng, because it uses
setjmp for exception handling, which triggers a compiler error due to
this settinng up been made twice. So a small patch to the current libpng
is part of this branch.

New tarball: http://download.savannah.gnu.org/releases/freetype/freetype
-2.5.2.tar.bz2

URL: http://trac.sagemath.org/15561
Reported by: charpent
Ticket author(s): Emmanuel Charpentier, Volker Braun
Reviewer(s): Volker Braun