[NEW PORT] audio/x42-plugins-lv2: Collection of LV2 plugins (submodules)

[ultima]

Summary

A collection of professional lv2 audio plugins written by Robin Gareus.

WWW: https://github.com/x42/x42-plugins/

PR\: 221199
Submitted by\: Yuri Victorovich (maintainer)
Reviewed by\: lifanov (mentor), matthew (mentor)
Approved by\: lifanov (mentor), matthew (mentor)
Differential Revision\: https://reviews.freebsd.org/DXXXXX

Test Plan

portlint:
WARN: Makefile: [36]: use ${VARIABLE}, instead of $(VARIABLE).
WARN: Makefile: Consider defining LICENSE.
WARN: Makefile: no port directory /usr/ports/audio/libltc found, even though it is listed in LIB_DEPENDS.
WARN: Makefile: no port directory /usr/ports/audio/zita-convolver found, even though it is listed in LIB_DEPENDS.
0 fatal errors and 4 warnings found.

1: false positive
2: couldn't find one
3, 4: up for review and must be added before this port

poudriere:
103i386
103amd64
110i386
110amd64
12i386
12amd64

[matthew]