[MERGE] Added support for a hook before sending the commit message to the editor.

[Monty Taylor]

John Arbash Meinel wrote:
> Alexander Belchenko wrote:
>> Alexander Belchenko has voted comment.
>> Status is now: Waiting
>> Comment:
>> why for it's needed?
> 
> I believe his idea is to be able to have a plugin set a default commit
> message based on what files have been modified, etc. It could also check
> to see if there is a merge, and set up a default message from that.

Indeed. In my case, it sets the stage for a plugin to populate the
commit message with any old commit messages that might have been
uncommitted... but other plugins could obviously inject other text into
the commit message.

Monty