fix bug in atomic cluster pgorder calculation

During check_match() the rotational alignment should not be
re-optimized.  This was giving false matches, making the point group
order larger than it should be.

pgorder for the LJ6 and LJ75 global minimum are now computed correctly.

I've not yet fully checked that this does not cause any other problems
add some more tests for point group order

test against two database of structures (LJ13 and LJ75) where the
correct values were calculated with OPTIM
forgot to add the new testing data files to setup.py
fix my fix of the test data file
fix dumb syntax error in setup.py
improve fix for pgorder

This commit reverts tht changes to exact_match

the point group order script now checks whether a rotation is unique
before incrementing point group order
clean point group order calculation a bit
Merge pull request #25 from js850/fix_pgorder

fix atomic cluster point group order bug and add tests