Comment 1 for bug 610341

This is three separate changes:

  - Rename 'tkdo cal --all' to 'tkdo cal --floating', to make it more clear what that option does.
  - Add 'tkdo cal --non-due' or similar, to include tasks which don't actually have a due date.
  - Replace the license symlink.

... and also, possibly add an option to filter the non-due tasks with a different (or additional?) pattern than the due tasks. For example, include all due tasks but only active non-due tasks.