Support OS X 10.10

OS X Yosemite ships with ruby 2.0. Most of the commands inside the
bundle work fine with the new interpreter. Currently “Keep current file
as reference” and “Complete across current tabs” are the only commands
which need ruby 1.8. To support these commands we use the ruby 1.8
interpreter bundled with TextMate.
Merge remote-tracking branch 'sanssecours/master'