that has actually been know for awhile.
There are a few mods that let you do that. Dartcraft's wrench can move spawners. I forget which one but one mod as something called a PortaSpawner that lets you pick them up.
But really the go to for mob spawning these days is either SoulShards or MFR if you need contorable mob spawning. Or Extra utilies if you just want a lot of random mobs.