Fixed issue with newer versions of Ruby on OS X Mavericks.
Merge pull request #13 from mhaddl/master

Fixed issue with newer versions of Ruby on OS X Mavericks.
Add “Open Terminal” (⌃⇧O) to file browser’s action menu

Closes textmate/textmate#1046.
Make Open Terminal command use system ruby.

Fails with Ruby 1.9
Send 'clear' after cd'ing to dir in Open Terminal command.
Make 'Open Terminal' open a new terminal tab.
Remove keybinding for 'Execute Line and Replace With Result'.

We use ^R for RSpec (run in terminal), instead.