Extract duplicate code to separate module.
Add Menu implementation.
Tidy up.
Inspect classes.

Little debugging method to allow the viewing of a class, it's methods
and the local variables set within.
Add further notes regarding width and height.
Add Coordinate class.

This class provides a better mechanism for designing and using
interfaces and will supersede Geometry in the near future.

The ExampleApp has been updated to reflect its use.
Add method to report the centre of the terminal.
Bail early if value empty.
Remove Foreground and Background classes.

Colour now provides the original HTML/CSS values when calling the
#to_json method. This caused Foreground and Background to no longer be
required.