[MERGE] make 'push' default to parent branch

[Stephen J. Turnbull]

Robert Collins writes:

 > Totally, and that is a really big win for bzr and tools like it :). But
 > this seems to affect people that *have already used bzr*. (How else can
 > you tell how hard it is ?)

By moving the workflow stuff in the tutorial to the end, or even a
separate document, maybe?  For most people, all they need for personal
use is install via their PMS, then init, commit, log, and diff from bzr.