0.5.3

• Default DATETIME columns to NULL in ClientJobsDAO for compatibility across mysql versions. As of mysql 5.7.8, values of 0 are not allowed for DATETIME columns, and CURRENT_TIMESTAMP is semantically inappropriate for those columns.
• Suppress this optional dependency on matplotlib without logging, because python logging implicitly adds the StreamHandler to root logger when calling logging.debug, etc., which may undermine an application's logging configuration
• Bugfix: Write the 'actualValues' to the output, don't reassign the output
• Fixed Username Regex in ClientJobsDAO
• cleaned up region a bit to make it compliant with numenta's coding guidelines.