Changelog:
This update adds a GUI to the navigation.

• Fixed the check for /goto, which wouldn't make it possible to use it.
• Added the command /navigation, which shows /goto in GUI form.
• Added the alias /gotogui for /navigation.
• Added the permission: mojangmaps.using.navigation for /navigation.
• Added a timer for /goto and /navigation to see how long it takes to calculate a path.
• Added the following translation strings (for people with custom messages): calcins, navigation
  For the full changelog, go to the commits of the 1.5 branch.

Any issues/ideas can be reported on the GitHub issues page.