Changed the way item rotation offsets are treated

Item rotation offsets are now optional. You can pass applyrotoffsets as
0 to CreateItem/InWorld to make rx/ry/rz parameters absolute so itemtype
specific rotation offsets aren't applied to these values (useful for
specifically placed items such as in a map, on tables, leaning against
walls, etc)

Passing 1000.0 as a rotation still applies the offset AS the rotation,
however this can also be done by passing 0.0 and applying the offsets.