External Applications: Open in iTerm (#580)

* application: main menu open in external terminal submenu has been added.

* application: system icons for preferences have been added.

* kit: view controller utilities external terminal tool shared user defaults key has been added.

* application: main menu preferences window tools tab has been added.

* application: document open in terminal action has been built on top of user defaults preferences.

* application: system toolbar icons have been removed due to key access.

* kit: base view controller utilities launch services locator has been added. Installed apps directory has been registered.

* application: main menu preferences window has been reverted back to two tabs.

* application: external applications open in iterm is running phase has been added.

* application: external applications open in iterm is not running phase has been fixed.

* application: main menu has been merged.

* application: document open in iterm give focus on start has been added.

* application: document open in iterm script example has been fixed.

* application: document open in terminal bring to front has been added.

* application: main menu preferences window advanced tab layout has been fixed.

Author: lolgear