Add MDTM support if supported by the FTP server, and if either

Add MDTM support if supported by the FTP server, and if either
timegm() exists or struct tm has a tm_gmtoff field (needed for
easily converting the time string to a GMT timestamp).
Escaping for ftp path arguments now uses a dedicated escaping
routine (in order to only escape globbing characters, not all
shell meta characters).
Execute the SIZE query with the same TYPE setting as the RETR transfer,
because the SIZE may be calculated differently for ASCII files.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@93128 13f79535-47bb-0310-9956-ffa450edef68