instead of passing "half" of the context wanted, just take the number of lines wanted. switch to a circular buffer to store the lines instead of shelling out (badly) to grep -C.

otherwise we may leave it NULL (it's set only in ctl_status) and crash in print_status.

better to use a control variable rather than `last' from a subroutine

This add a -f flag (that falls back to $AMUSED_STATUS_FORMAT) to control which field to print and in which order.

I've added a sufficient amount of code I guess