fixed dropping

i realized that i was calling actor.dropFromInv since it was a public
method and extended through entity, but Actor doesnt have a m_parent so
it would throw a nullPointerException because it was trying to access a
variable that didn't exist

now i fixed it. instead of going object.dropFromInv(thingToDrop), you go
entity.dropFromInv()
glaring id fix

i realized that m_id.remove(id) was removing by index instead of
removing by object, meaning that m_id.remove(34) would not remove id 34,
but instead the 35th thing (34 plus one because index 0 counts) in the
ID list