mq: re-phrase the qrefresh help about the user and date options

mq: add the date with qrefresh, even if missing (issue1768) When setting the date with qrefresh (-d|-D), and the patch does have neither a 'Date:' nor a '# Date' header, add the date field as such: - if the patch has a 'From:' header, add a 'Date:' header - otherwise, upgrade to Mercurial extended patch format and add '# Date'

mq: upgrade the patch to HG format when adding the author name with qrefresh When setting the author field with qrefresh (-u|-U), and the patch does have neither a 'From:' nor a '# User' header, add the author name as such: - if the patch has a 'Date:' header, add a 'From:' header - otherwise, upgrade to Mercurial extended patch format and add # From

mq: add function to check if a header exists in a patch

mq: fix coding style in qrefresh

Merge with crew-stable.

hook: fix full path imports on Windows (issue1779) Bottom portion fixes full path imports on source installs on Windows. The top portion further fixes full path imports on binary installs. Initial patch by Roman V. Kiseliov