[MERGE] Add revert --forget-merges

[Martin Pool]

This adds a new option to the revert command.  The technical effect of
this is that it resets the parent list of the working tree to just the
immediate parent.  To the user, this means that it clears out the
pending merges shown by bzr status.

This is not something I expect will often be used, but it can be handy
in some cases.  One of them is when you do a merge, then want to shelve
most of it and just cherrypick a few hunks, without recording the whole
thing as merged.  Another is that people sometimes want to commit an
'untracked' or 'collapsed' merge, basically losing the record of the
intermediate changes.

In older tree formats people could edit the pending merges list by hand;
that's not really practical any more and was never something we wanted
to encourage.  This gives a safer mechanism.

-- 
Martin
-------------- next part --------------
A non-text attachment was scrubbed...
Name: bzr-mail-jj7t3L.patch
Type: text/x-diff
Size: 7072 bytes
Desc: not available
Url : https://lists.ubuntu.com/archives/bazaar/attachments/20070924/ccabb6c7/attachment.bin 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
Url : https://lists.ubuntu.com/archives/bazaar/attachments/20070924/ccabb6c7/attachment.pgp