Added map set commands with varying levels of success
/nbt set map center [x] [z] (If x and z are not provided it defaults to player pos, I recommend using the default setting

/nbt set map scale 1->5 1 being 1:1 5 being the largest map
Made it so you can only set map center in loaded chunks so updates happen on request, I may eventually make it so that it will briefly load chunks required, but at the moment I don't see any use of setting map center in an unloaded area.

Added Potion effect and duration modifiers
/nbt set potion effect <VALID_EFFECT>
/nbt set potion duration <MINS:SECONDS>