url: extract password database from password manager So far password manager was keeping authentication information so opening new connection and creating new password manager made all saved authentication information lost. This commit separates password manager and password database to make it possible to reuse saved authentication information. This commit violates code checker because it adds add_password method (name with underscore) to passwordmgr object to provide method required by urllib2.

https://bz.mercurial-scm.org/1089

  $ hg init
  $ mkdir a
  $ echo a > a/b
  $ hg ci -Am m
  adding a/b

  $ hg rm a
  removing a/b (glob)
  $ hg ci -m m a

  $ mkdir a b
  $ echo a > a/b
  $ hg ci -Am m
  adding a/b

  $ hg rm a
  removing a/b (glob)
  $ cd b

Relative delete:

  $ hg ci -m m ../a

  $ cd ..