[MERGE] An EmailMessage class for bzrlib (v1)

[Ian Clatworthy]

John Arbash Meinel wrote:

> I'm guessing this isn't going into 0.18, but if it is, I'd be willing to
> clean up the one bit and merge it.

I haven't followed this thread closely but my perception is that this is
new library code not yet used by the higher layers? If that's true and
its had sufficient review, then it can certainly go into 0.18 assuming
it's merged before I cut the RC. (If my perception is right, then it's
an incremental improvement with very limited risk of breaking anything.)

Ian C.