hg: look up schemes using url.url

schemes: prevent one letter schemes from being interpreted as drive letters To allow one letter schemes, this makes the extension override url.has_drive_letter() to return False for any schemes defined. On Windows, the extension will raise util.Abort for any schemes that conflict with existing drive letters.

hgweb: use url.url when setting CGI environment variables

url: use url.url in proxyhandler

httprepo/sshrepo: use url.url Like the previous patch to getauthinfo(), this also makes username/password parsing more forgiving for SSH URLs. This also opens up the possibility of allowing non-numeric ports, since the URL parser has no problem handling them. Related issues: - issue851: @ in password in http url - issue2055: nonnumeric port bug with https protocol

url: use url.url in url.open()