Gather key signatures at top level

Signed-off-by: Ray Lehtiniemi <rayl@mail.com>
Bump copyright dates

Signed-off-by: Ray Lehtiniemi <rayl@mail.com>
Add comment markers for staves in next section

Signed-off-by: Ray Lehtiniemi <rayl@mail.com>
This section looks do-able with only two voices

Signed-off-by: Ray Lehtiniemi <rayl@mail.com>
Add bars for each individual measure

Signed-off-by: Ray Lehtiniemi <rayl@mail.com>