icu: bump to 53.1

Wanted to fix a test, turns out 53.1 still fails.
But upstream fixed it in svn :-)

Let's do the time warp again: http://erack.org/blog/index.php?/plugin/tag/TestTwoDigitYear

Change-Id: I0eb3f7977d5c286ff785a2a9ad3e147ecc2f48c1
app-editors/vim-runmtime: enable syntax highlighting as default

Change-Id: I3aefbdd8c9c16665b34556457d286cfe62fe383d