multiindex support

Basic support for multi/hierarchical indices in SQLite and Postgres SQL.

Use parameters highest=(index_0_max, index_1_max), lowest=(index_0_min, index_1_min) to filter

postgresql support

tested to support postgresql and sqlite.

additional table functions to manipulate databases directly from pandabase, making it less likely that you will need to use SQL directly to deal with one-off situations like removing tables, etc.

bugfix - now coerces bool to float/int if necessary to match existing database column

first release

SQLite only, but works good!

now pip-installable with:
pip install pandabase==0.1.1