icu 51.1 (51_rc)

git-svn-id: svn://tug.org/texlive/trunk/Build/source@29305 c570f23f-e606-0410-a88d-b1316a301751
graphite2 1.2.1

git-svn-id: svn://tug.org/texlive/trunk/Build/source@29306 c570f23f-e606-0410-a88d-b1316a301751
Fix uninitialized variables
Make the shapers array is really NULL-terminated