Installing 'update-copyright' on PQM

[Robert Collins]

I think Martin's case is an important one.

Consider bzrlib/util/*

None of the files in there has commit records matching their copyright
dates, and we do not have the right to strip their copyright dates.
The current algorithm, on PQM, would mangle things at the first change
made to those files (and they do, rarely, change). Worse still, we
couldn't change it at all because the plugin would insist on winning.

I agree with the already pointed out concept of there being multiple tasks:
 - auto resolve copyright merges
 - auto add files *changed by the user* to copyright lines
(specifically excluding converged merges of a file)
 - audit the history of a file vs its copyright header and report/adjust

Of those three, I don't see any issue with fairly simple algorithms
doing the first two automatically.

I think the third has enough corner cases, required exclusions and
general gotchas that it should be a different thing.

-Rob