ruby: update to 2.1.2.

This revamps and simplifies the ruby template.
ruby now subsumes ruby-rdoc, ruby-irb and ruby-gems.
ruby-ri stays separate because of size, but has an exact dependency.

Added patches for LibreSSL (removal of RAND_egd) and libffi detection.
vim: update to 7.4.373.

Rebuild for ruby-2.1.2.
weechat-ruby: rebuild against ruby-2.1.2