sysutils/vchanger: Add the port to the tree
Vchanger is a disk-based virtual autochanger that may be used with the Bacula
Open Source network backup system to emulate a magazine-based tape autoloader

PR: 219046
Reported by: ml@netfence.it
Reviewed by: mat (mentor) mmokhi
Approved by: mat (mentor)
Differential Revision: https://reviews.freebsd.org/D10598