Add -T option to mark all notes as done

Command line option -T now marks all notes with flag U to DONE (D)

Signed-off-by: Niko Rosvall <niko@ideabyte.net>
Add -T option documentation

Signed-off-by: Niko Rosvall <niko@ideabyte.net>
Add INSTALL file

Signed-off-by: Niko Rosvall <niko@ideabyte.net>
Fix typos

Signed-off-by: Niko Rosvall <niko@ideabyte.net>
Fix a typo

Signed-off-by: Niko Rosvall <niko@ideabyte.net>