MFH: r408848

Fix dependencies: x265, opus, twolame, fribidi

x265 was not correctly detected due to link attempt to libdl.
Also avidemux now automatically detects the presence of opus,
twolame and fribidi during configure and builds additional
plugins for them.
This changeset introduces new OPTIONS FRIBIDI OPUS TWOLAME
(all non-default) and fixes plugins pkg-plist.
Bump PORTREVISION for avidemux-*

PR: 206945
Submitted by: mi
Reviewed by: riggs
Approved by: ports-secteam (feld)