Datatoolbelt

Feature
* **pandastools.py:** Add count_share to profile ([`2dcb702`](https://github.com/estripling/datatoolbelt/commit/2dcb702786c37033532449391eee070f738c1280))
* **pandastools.py:** Add freq_columns ([`6798f73`](https://github.com/estripling/datatoolbelt/commit/6798f7330fb84128cd279fe3738e7f6541bcb6ab))

Feature
* **pandastools.py:** Add profile ([`41b2f8d`](https://github.com/estripling/datatoolbelt/commit/41b2f8d5658af66e92efc31ce5298378847f7705))
* **pandastools.py:** Add dropna parameter to freq ([`f01cf1f`](https://github.com/estripling/datatoolbelt/commit/f01cf1f09ac4b86322aef13d96edd7e7b49c59bf))
* **pandastools.py:** Add mode ([`3e0e255`](https://github.com/estripling/datatoolbelt/commit/3e0e2551c559bd129b33c10bbda7c5a275c16d78))
* **pandastools.py:** Add dropna parameter to entropy and efficiency ([`5b5920d`](https://github.com/estripling/datatoolbelt/commit/5b5920d8c42564f458430136ebf6aed07e6799e4))
* **pandastools.py:** Add efficiency ([`f9c5966`](https://github.com/estripling/datatoolbelt/commit/f9c59666b9e2b40f32eb9aa7928c681024f119b4))
* **pandastools.py:** Add entropy ([`a866aef`](https://github.com/estripling/datatoolbelt/commit/a866aef9cf7baf8391205699ec2c2bf5dee95509))
* **pandastools.py:** Add union_dataframes_by_name ([`4f8ede1`](https://github.com/estripling/datatoolbelt/commit/4f8ede131f4c7182c2d108849ff433ffa49d3c24))
* **pandastools.py:** Add join_dataframes_by_index ([`e42f9ad`](https://github.com/estripling/datatoolbelt/commit/e42f9ad6ae1077c943a341ad17e388479f272060))
* **pdtools.py:** Add join_pandas_dataframes_by_index ([`075c7d3`](https://github.com/estripling/datatoolbelt/commit/075c7d38dbdd91333fd732aa779ac0ca2b96ccbc))

Documentation
* **freq:** Improve docstring ([`42adda0`](https://github.com/estripling/datatoolbelt/commit/42adda0c56db0574ce468966cfe21cd27e5c7954))
* **union_dataframes_by_name:** Add deduplication note ([`acd5ebc`](https://github.com/estripling/datatoolbelt/commit/acd5ebc4f9ae2b4443570f9c84ac9c2e53990319))
* **freq:** Improve docstring ([`3178b7a`](https://github.com/estripling/datatoolbelt/commit/3178b7a84060a1b068bff4a988bbe90301af2758))

Feature
* **pdtools.py:** Add freq ([`34f74fb`](https://github.com/estripling/datatoolbelt/commit/34f74fbdede768f13c23ff912f1e296c4026f06e))