Catch urllib's HTTPException and give a meaningful error message to the user. Usually urllib only throws HTTPError exceptions, which already are a subclass of IOError.

add --config global option. allows to set hgrc option on command line. syntax: --config section.name=value also add new test-globalopts to test all global options in one place.

allow to send email using sendmail. default is still smtp. update hgrc doc with sendmail info.

merge with crew.