Implement $Hg$ scheme with update hook
The pivotal line for update hook is:
repo.dirstate.update(kwupdates, 'n')
This forces hg to consider the freshly written files as not modified.
Thanks to wfile(), this keeps executable bits etc.
Still needs more testing.
No need to check for basename/filename in keyword trigger.
update hook does not need re.
TODO:
Walk back in history, if last change of file didn't happen in 1
of the provided changesets (update/merge?)?
syntax: glob
*.pyc
*~
*.swp
*.orig
*.rej