use numbers for richer control of ToCs

Ticket

use numbers for richer control of ToCs+status
use numbers for richer control of ToCs+priority
use numbers for richer control of ToCs+tag
use numbers for richer control of ToCs+commit
 

 

use numbers for richer control of ToCs+solution

Instead of PlainText that's on/off, +*table of contents cards are now of type Number. If there are at least as many headers in a card as that number, then a table of contents will be shown at the top of the card. If the number is zero, then there will be no table of contents no matter how many headers there are.