l.s.w.url : module documentation

Teach the urlparse module about the sftp scheme.

That allows the helpers in this module to operate usefully on sftp URLs. This fix was suggested by Jamesh Henstridge and is said to be used by bzr and other unrelated projects.

Without that, some operations on sftp URLs give obviously wrong results. For example: urlappend('sftp://foo/bar', 'gam') => 'gam'

>>> urlappend('sftp://foo/bar', 'gam')
'sftp://foo/bar/gam'

Teach the urlparse module about the bzr+ssh scheme.

That allows the helpers in this module to operate usefully on bzr+ssh URLs

>>> tuple(urlparse('bzr+ssh://example.com/code/branch'))
('bzr+ssh', 'example.com', '/code/branch', '', '', '')