System for loading bayeslite sessions into a bdb

[marcoct]

[marcoct]

Work begun on this branch: https://github.com/probcomp/bdbcontrib/tree/20151029-marcoct-session-analysis

[marcoct]

List of remaining items:

• Allow for proper handling of types for the various columns (and extracted features)
• Testing

[gregory-marton]

@marcoct , a quick status update?