Merge remote-tracking branch 'upstream/master'
initial set of changes introducing python3 support
require at least boost v1.45
get some of the pickle problems resolved; this probably only works with python3 and is not yet 100% functional
ugly fix to get the rdchem tests working
this does not seem like the right way to be doing things longterm
more pickle cleanups
python2 fix
undo a couple un-necessary changes and, hopefully, get this working with python2 again
clean up some leaks in one of the tests
another python3 test failure fixed
fix FreeChemicalFeatures pickling and some syntax problems in testFeatures.py
fix DbCLI tests; includes fixing the pickling of SparseIntVects
fix a backwards compatibility problem
clean up another batch of missed ResourceWarnings
should fix python2 compatibility problem
really fix the python2 problems this time?
<sigh>
switch generate_fraggle_fragmentation to return a sorted list of fragments; this clears up a difficult-to-understand problem with the python3 port
python3 cleanup
fix some more tests