Merge pull request #260 from emorency/feature/OPAL-1910-System-config

OPAL-1910: Server general config administration UI
OPAL-1926 - Added comment as a QueryParam to relevant view and variable REST calls
Merge pull request #261 from kazoompa/feature-OPAL-1926

OPAL-1926 - Added comment as a QueryParam to relevant view and variable REST calls
OPAL-1911: Created installation/upgrade steps for general config
Exception when databases are empty
OPAL-1911: Upgrade/install step for opal general config