Log Message:
Update graphics/giflib to 5.1.4.

Changes:
Version 5.1.4
=============
Code Fixes
----------
* Fix SF bug #94: giflib 5 loves to fail to load images... a LOT.
* Fix SF Bug #92: Fix buffer overread in gifbuild.
* Fix SF Bug #93: Add bounds check in gifbuild netscape2.0 path
* Fix SF Bug #89: Fix buffer overread in gifbuild.

Version 5.1.3
=============
As of this version the library and code has been seriously abused by fuzzers,
smoking out crash bugs (now fixed) induced by various kinds of severely
malformed GIF.

Code Fixes
----------
* Prevent malloc randomess from causing the header output routine to emit
  a GIF89 version string even when no GIF89 features are present. Only
  breaks tests, not production code, but it's odd this wasn't caught sooner.
* Prevent malloc randomess from producing sporadic failures by causing
  sanity checks added in 5.1.2 to misfire.
* Bulletproof gif2rgb against 0-height images. Addressed SF bug #78:
  Heap overflow in gif2rgb with images of size 0, also SF bug #82.
* Remove unnecessary duplicate EGifClose() in gifcolor.c. Fixes SF bug #83
  introduced in 5.1.2.
* Fix SF Bug #84: incorrect return of DGifSlurp().