New Multi-Processed, In-Memory DB Builder

Implemented a new multi-processed Database Builder that uses a shared
Manager dictionary to record the words, which is then batch-written to
SQL at the end. This results in a *significant* speedup (~4 hours vs. 41
hours previously with same test texts) at the cost of slightly higher
memory usage and no recourse in event of interruption.

Including tqdm (https://github.com/noamraph/tqdm) for better tracking of
progress. See tqdmLICENSE.

Mimicking MIT license for my own work with LICENSE.