Merge branch 'release/0.16' into develop
Adds multiple implementation options for MySQL.
Adds tuning options for database drivers (connection string may be enhanced with options).
Adds sqlalchemy plugin py-postgresql, if psycopg2 not available. Lists found drivers with --version.
Adds pg8000 plugin.
Adds tests for escape_keyword.
Adds tests for options.restriction and .format_value.
Adds tests for exception, logger, model.databaseconnection.
Fixes #4.
Implements #5 (dry run).
Adds the alfred-workflow library to display items within Alfred.
Adds the OR operator (|). Adds tests for sources.
Version bump to 0.17.0.
Merge branch 'release/v0.17.0'