setup: fixed for Pythons which don't have a CFLAGS

Specifically this is observed to happen on the PyPy one gets from homebrew

--HG--
branch : stable
extra : amend_source : d8bd2e6b6e80498ac2ccfe57980a4744bde50913
bugzilla: correct config documentation error

The config documentation specifies the wrong access method in the XMLRPC+email
configuration.

--HG--
branch : stable
extra : rebase_source : 3110f5f4f94a27034d0eed98589bbfdf5d44fbe8
bookmarks: avoid deleting primary bookmarks on rebase

Prior to this, doing "hg rebase -s @foo -d @" would delete @, which is
obviously wrong: a primary bookmark should never be automatically deleted.

This change blocks the deletion, but doesn't yet properly clean up the
divergence: @ should replace @foo.

--HG--
branch : stable