Python3 compatibility issues in lalburst

Flake8 reports the following python3-compatibility issues in lalburst:

./lalburst/python/lalburst/packing.py:94:10: F821 undefined name 'cmp'
./lalburst/python/lalburst/bucluster.py:154:9: F821 undefined name 'cmp'
./lalburst/python/lalburst/bucluster.py:154:30: F821 undefined name 'cmp'
./lalburst/python/lalburst/bucluster.py:154:59: F821 undefined name 'cmp'
./lalburst/python/lalburst/bucluster.py:154:86: F821 undefined name 'cmp'
./lalburst/python/lalburst/bucluster.py:163:9: F821 undefined name 'cmp'
./lalburst/python/lalburst/bucluster.py:163:30: F821 undefined name 'cmp'
./lalburst/python/lalburst/bucluster.py:163:59: F821 undefined name 'cmp'
./lalburst/python/lalburst/bucluster.py:173:9: F821 undefined name 'cmp'
./lalburst/python/lalburst/bucluster.py:173:30: F821 undefined name 'cmp'
./lalburst/python/lalburst/bucluster.py:173:59: F821 undefined name 'cmp'
./lalburst/python/lalburst/offsetvector.py:205:10: F821 undefined name 'cmp'
./lalburst/python/lalburst/cafe.py:215:10: F821 undefined name 'cmp'
./lalburst/python/lalburst/binjfind.py:78:9: F821 undefined name 'cmp'
./lalburst/python/lalburst/calc_likelihood.py:96:8: F821 undefined name 'unicode'
./lalburst/python/lalburst/snglcoinc.py:720:13: F821 undefined name 'reduce'

It would be very nice to get these fixed.