Like the title said, a plugin that allow players to place mushrooms (Ids 39 and 40) dont matter sunlight level. No commands, maybe a permission like mushroom.place. Nothing more, Thanks. BlockWar.
Now, don't yell at me if I'm wrong, but I don't believe that mushrooms could ever be placed in sunlight. I tried doing this plugin and it would never place it anywhere out of dark. Maybe someone can come along and help you.
You can't place them in sunlight, they just generate in sunlight. They use TerrainControl for that feature. The request is still possible in one way or another.
BlockWar I believe that garrison means that they use a terrain controlling plugin to generate a world with the mushrooms in the sunlight. So they have to create an entire new world with the mushroom in the sunlight by default. I've never used it so I couldn't tell you how to do it.