Updated MEASURE file writing to mimic new input format.
Updated MEASURE file writing to mimic new input format.

This requires writing the collisionModel attribute of each species that
has one, as well as replacing the collisionModel() block with just the
bathGas = {...} part.

enochd/RMG-Py,KEHANG/RMG-Py,chatelak/RMG-Py,pierrelb/RMG-Py,comocheng/RMG-Py,nyee/RMG-Py,pierrelb/RMG-Py,chatelak/RMG-Py,enochd/RMG-Py,faribas/RMG-Py,nickvandewiele/RMG-Py,nickvandewiele/RMG-Py,faribas/RMG-Py,comocheng/RMG-Py,nyee/RMG-Py,KEHANG/RMG-Py