x11-fm/4pane: new port had been added (+)

4Pane is a multi-pane, detailed-list file manager for Unix-like
systems. It is designed to be fully-featured without bloat, and
aims for speed rather than visual effects.

The program relies on some GNU/Linux utilities and API to manage
disks and mounts. Non-portable calls to getmntent(3) et al. had
been replaced with our native getmntinfo(3) ones. However, full
storage support is still lacking, owing to limited blkid(8) and
lsblk(8) functionality and inconsistent naming of different file
systems between GNU/Linux and FreeBSD.