initial implementaion of displaying world coordinates, also for overlay coords
bound preferences for display coordinates to key events
displayed world coordinates are now formatted
wrapping coordinates for longitude type, now displays world coords for data cubes
doesn't depend on formatter_locator's spacing anymore
fixing formatting issue for world coordinates
removed unused code
moving format_value method to coordinate_helpers
had accidentally moved the code for setting self.patch
added unit tests and changelog entry
Merge pull request #112 from anizami/world-coordinate

Displaying world coordinates in interactive mode