Adds Keep Alive Feature, Bug Fixes, Performance Improvements

This update includes a new feature to the Max Retries device configuration parameter:

• -1 [NEW] means that the device will not be automatically disabled regardless of the number of communication failures (e.g., "keep alive."),
• 0 means that the device will be automatically disabled upon the first communication failure, and
• 1+ means that the device will be automatically disabled upon reaching the indicated number of communication failures.

In addition, this update includes:

• bug fixes, and
• performance improvements.