Added ".yardopts".

Also removed the "doc-server" rake task since ".yardopts" makes that
superfluous.
Added module functions for writing files.
Updated gitignore.
Waypoint#display_format now uses symbols.

Additionally, removed symbols for Waypoint#symbol since Ozi Explorer
supports multiple symbol sets.
Updated documentation.
Bumped project version.
Improved test runner.
Fixed a bug in Rozi::Track.

It didn't use interpret_color for #color=.
Added tests for Rozi::OziFunctions.
Added some text to test runner.
Added Ozi Explorer's datums to Rozi.

This includes the whole list of valid datums as well as a module-function
for checking the validity of a datum string.
Added NST writing capabilities.
Test task now prints all selected test files.
Updated README.rdoc with info about NST files.
Improved set-version task.

Now updates the gemspec date as well.
Bumped project version.