Fix update schema.
Update output message for simulate
Add seconds support and store diagnostics for ANALYZE
Fix tests so they pass again (they weren't updated to reflect code changes)
Add ability to set model config in INITIALIZE MODELS.

Now, you can pass "WITH CONFIG <model_config>" to INITIALIZE MODELS.
<model_config> lets you set the column initialization, row initialization,
and kernel list. By default, CrossCat is used, but you can use
WITH CONFIG naive bayes or WITH CONFIG crp mixture to use those two
simplified models instead.
Add initial implementation of show diagnostics. Currently only shows iterations and model config.
Remove rounding of continous data.
Fix INFER: now behaves like impute, instead of using marginals.
Convert SIMULATE WHERE clause to GIVEN clause.
DROP MODELS working
Recategorize PROBABILITY OF col=value as column-aggregate function (instead of normal function)
Columns are now always case-insensitive
Fix INFER bug where imputed cells with code 0 were not filled in.
Merge branch 'hist'
Add pandas to install_requires
Merge branch 'master' of https://github.com/mit-probabilistic-computing-project/BayesDB into hist