[MERGE] Add InterBranch.push().

[Jelmer Vernooij]

Aaron Bentley wrote:
> Jelmer Vernooij wrote:
>> This patch moves the functionality of Branch.push() to InterBranch.push(), 
>> so it can be overridden when necessary. For example, this is useful for bzr-svn
>> so it provide a faster push.
> 
>> Similar to my InterBranch.pull() patch, this patch duplicates some of the tests 
>> for Branch.push() for InterBranch.push(). It might be useful to trim the 
>> Branch.pull() tests if this lands.
Sorry, that actually should've said "It might be useful to trim the
Branch.push tests if this lands."

> Would it be possible to implement Branch.push as InterBranch(target,
> self).pull() ?
These functions have different return types and trigger different hooks,
but share a common worker function 'update_revisions', that already
exists on InterBranch and does the bulk of the work. Despite this, the
current pull/push implementations are quite different at the moment.

Cheers,

Jelmer