Hotfix/1.6.9

Improved the TerminalCommandService to use bash instead of open
Fixed no callback being fired when a return file doesn't exist on the TerminalCommandService
Fixed the scriptFinished event on the TerminalCommandService sending NULL instead of an empty array as for the return scripts on failure
Fixed the TerminalCommandService not functioning on OSX Yosemite
Fixed the .command file not being removed after the command has been ran for the TerminalCommandService
Updated .gitignore to ignore the OSX DS_Store files