Land "avoid XMLRPC" for bzr-2.3.?

[Martin Pool]

Thanks for chasing that up.  According to the bug the benefits are:

> * xmlrpclib is an external dependency with some bugs like bug 186920

This is not particularly going to help people who have already managed
to get a 2.3-series release installed.

> * it's inconsistent with other API-type services on Launchpad
> * it's also inconsistent at the code level with the mechanisms used by bzr

True and good to clean up but not a reason to backport it.

What else?

 * It causes some problems with quirky proxies

True, but people using 2.3 have probably either solved this in their
proxy configuration, or through our workarounds, or installed a later
bzr, (or given up.)

 * It wastes time doing an unnecessary round trip

Excellent to fix, but generally we don't do performance fixes into 2.3
unless they're extremely safe, and I'm not sure this is, because it
interacts so much with so many weird and broken external systems.

 * It will let Launchpad drop this interface eventually.

Removing it from 2.3 updates doesn't really help; we need 2.3 and
earlier to EOL entirely before they can do that.

Unless I missed something I don't think we should put it in 2.3.

Martin