tests/test-bdiff.py.out

hg: establish function for performing post-share actions

As part of writing an extension that wished to share an arbitrary piece
of data among shared repos, I had to reimplement a significant part of
hg.share in order to obtain localrepository instances for the source
and destination.

This patch establishes a function in hg.py that will be called after a
share is performed. It is passed localrepository instances so extensions
can easily perform additional actions at share time. We move hgrc and
shared file writing there because this function is a logical place for
it.

A side effect of the refactor is writing of the shared file now occurs
before updating. This seems more appropriate and shouldn't have any
impact on real world behavior.

*** 'a\nc\n\n\n\n' 'a\nb\n\n\n'
*** 'a\nb\nc\n' 'a\nc\n'
*** '' ''
*** 'a\nb\nc' 'a\nb\nc'
*** 'a\nb\nc\nd\n' 'a\nd\n'
*** 'a\nb\nc\nd\n' 'a\nc\ne\n'
*** 'a\nb\nc\n' 'a\nc\n'
*** 'a\n' 'c\na\nb\n'
*** 'a\n' ''
*** 'a\n' 'b\nc\n'
*** 'a\n' 'c\na\n'
*** '' 'adjfkjdjksdhfksj'
*** '' 'ab'
*** '' 'abc'
*** 'a' 'a'
*** 'ab' 'ab'
*** 'abc' 'abc'
*** 'a\n' 'a\n'
*** 'a\nb' 'a\nb'
6 6 'y\n\n'
6 6 'y\n\n'
9 9 'y\n\n'
done
done