Install iTerm2 and set the theme

• Modified .cask file to install iTerm2 and add Tomorrow Night theme.
• Add Preferences for sublime text in .init folder
• Removed .sublime-* from global git ignore
• Update .osx file to update iTerm2 with new theme
Add tab git completion for commands and branches
Add git tab completion

* develop:
  Add tab git completion for commands and branches
  Install iTerm2 and set the theme