charts and sequences updates

The charts and sequences team has been busy updating old and creating
new sequences for AAVSO variable star charts.

Tom Bretl and Tim Crawford in particular have been very ambitious, and
I would like to extend my own personal "thank you for a job well
done". They have devoted literally hundreds of hours of work to this
effort in the last couple years, resulting in almost 600 chart
revisions.

Many of the recent changes were possible because we now have reliable