Bugfix - Fixing init assertions and rotations
Bugfix - Fixing init assertions and rotations

The assert statements were not appropriate, only checking for class, I
now check for subclass which makes everything work nicer. Also checking
the input data rather than once it has been assigned.

Also was not querying the appropriate data from the TransRotData object
for the rotations.

malramsay64/MD-Molecules-Hoomd,malramsay64/MD-Molecules-Hoomd