Python 3 support

[John Vandenberg]

At least a few syntax errors

$ python3.10 -m pyflakes grasp/
grasp/grasp.py:311:17: Missing parentheses in call to 'print'. Did you mean print(...)?
                print "Exception encountered in test for equality, assuming unequal..."
                ^
grasp/magic.py:495:13: Missing parentheses in call to 'print'. Did you mean print(...)?
            print 'Remove Out entries: %s' % keys
            ^
grasp/test/test_grasp.py:93:22: invalid decimal literal
                     1L, # Long
                     ^