Readme, doc updates.

Adding JSON output and related command-line command. Releasing new ve…

…rsion.

Sentence can be converted to a dict, so that it can be encoded in, e.…

…g., JSON.

Adding ability to filter by date. Now aisgrep has --after and --befor…

…e options.

Bumping version number to 0.6.4 for release.

Bump version number for release.

Bumping version number for release.

Making sure the magic JSON file gets deployed.

Deploying to the package library.