url: abort on file:// URLs with non-localhost hosts

url: special case bundle URL parsing to preserve backwards compatibility This allows bundle://../foo to continue to refer to the relative path ../foo (bundle URLs do not take host names).

url: add trailing slashes to URLs with hostnames that don't have one This works around a potential issue in Python 2.4 where cloning a repo with a URL like http://foo:8080 would cause urllib2 to query on http://foo:8080?cmd=capabilities instead of http://foo:8080/?cmd=capabilities. In the past, this issue has been masked by the fact that url.getauthinfo() added a trailing slash when it was missing.

url: move drive letter checking into has_drive_letter() for extensions This will let the schemes extension override drive letter detection to allow single letter schemes.

changegroup: unnest some lookup functions

changegroup: minor ordering and renaming changes for similarity This eliminates some needless differences between the two changegroup variants

changegroup: remove nodeiter temporary

changegroup: refactor prune as a filter

changegroup: add first logic to send file header This will allow us to later change how we filter needed file nodes

url: fix tests