https://github.com/jezdez/textmate-missingdrawer
Changing the terminal application launched from the sidebar
By default, the “open terminal window” button launches the Terminal application. To use iTerm, run
$ defaults write com.macromates.TextMate TerminalLauncherAppName "iTerm" To reset back to Terminal, run
$ defaults write com.macromates.TextMate TerminalLauncherAppName "Terminal"