Append MiniDLNA to the main Plugins tree menu node

Merge:	releng/9.1.0
(cherry picked from commit af432249584ee9b7b2e1543e748b194048edcc14)
Append Firefly to the main Plugins tree menu node

Merge:	releng/9.1.0
(cherry picked from commit 88c79e7e2698f2bb290e40ccde748505180014b4)