[PATCH 0 of 4] Patches for hg -R xy pull/incoming, and bundle:..+..-style URL semantics

[Peter Arrenbrecht]

Hi all,

This patch series addresses bugs

  http://www.selenic.com/mercurial/bts/issue820
  http://www.selenic.com/mercurial/bts/issue821

It contains two changes that need particular attention:

* I added an additional parameter, "mainrepo", to hg.repository()
  and *repo.instance(). This is used to properly set a bundlerepo's
  parent repo when -R is active.
  
* I changed bundlerepo.instance() so that "bundle://...+..."-style 
  URLs are interpreted as bundle+repo, rather than repo+bundle.
  This aligns bundlerepo.instance() with bundlerepository.__init__().
  I chose bundle+repo because this does not break any tests.
  Fixing __init__() to use the repo+bundle format broke test-bundle.
  The main problem is that both formats are currently exposed by
  public APIs:
  - repo+bundle is today accepted in bundle://repo+bundle URLs
    by bundlerepo.instance().
  - bundle+repo is today set by __init__ and passed on to hooks.
  So this needs some thought by people more familiar with the
  bundle repository design. I have posted the current patch to 
  highlight the issue.

-peo