Summary: Also change the internal API so it no longer accepts the "heads" argument.
Reviewed By: ryanmce
Differential Revision: D6745865
fbshipit-source-id: 368742be49b192f7630421003552d0a10eb0b76d
af9f7f376059 introduced a bug: emails Content-Transfer-Encoding
is silently replaced with 'quoted-printable' while any other
encoding could be used by underlying code. The problem is revealed
when a long unicode line is encoded.
The patch implements proper check which works for any text and
encoding.
Add the -B/--bookmark option to select a bookmark whose changesets
and its ancestors will be selected unless a new bookmark/head is
found.
This is inspired by hg strip -B option.
