basectx: add _matchstatus method for factoring out last of parentworking logic
This patch paves the way to allow a workingctx to override the match object
with a custom 'bad' method for cases where status is sent a directory pattern.
all()
draft()
::tip
draft() and ::tip
::tip and draft()
0::tip
roots(0::tip)
author(lmoscovicz)
author(mpm)
author(lmoscovicz) or author(mpm)
author(mpm) or author(lmoscovicz)
tip:0
max(tip:0)
min(0:tip)
0::
min(0::)
roots((tip~100::) - (tip~100::tip))
::p1(p1(tip))::
public()
:10000 and public()
draft()
:10000 and draft()