new hashing algorithm for path-based fingerprints pass 1;
definitely some optimization work left to do, but this works and passes tests

git-svn-id: svn://svn.code.sf.net/p/rdkit/code/trunk@2442 a5045d30-4826-4484-9c7f-6e55a06ddc77
patch from Roger S to include CTAB aliases

git-svn-id: svn://svn.code.sf.net/p/rdkit/code/trunk@2443 a5045d30-4826-4484-9c7f-6e55a06ddc77
version number bump and some optimization work

git-svn-id: svn://svn.code.sf.net/p/rdkit/code/trunk@2444 a5045d30-4826-4484-9c7f-6e55a06ddc77