Suggest DRI option for FreeBSD.
This lets the build fail further.
Treat FreeBSD and NetBSD uniformly. This fixes building the package on FreeBSD.
Update ruby-tw to 0.5.1.  (leaf package update)

Changes from History.txt:

=== 0.5.1 2013-09-18

* tweet with file  % tw 'yummy!!' --file=food.jpg
Updated net/ruby-tw to 0.5.1
Don't bother with unused functions for Clang. Race conditions while
building.
Don't bother with unused functions for Clang.
Reset maintainer, address bounces.