Marco Beishuizen <mbeis@xs4all.nl> takes maintainership of 3 ports

Ports: x11-fm/pcmanfm-qt/ x11/libfm-qt x11-themes/cursor-dmz-theme

PR: 226294 226305 226309
Submitted by: Marco Beishuizen <mbeis@xs4all.nl>
Approved by: tcberner (mentor, implicit)