Finished tab config functionality. Still needs some more refactoring.
Unified healthcheck/monitoring plugins. #14
 Fixed typo.
Refactored tab blocks.
Refactored log widgets into generic tail widget.
Fixed array reindex in initConfig()
Refactored modules tab contents as widget.
Refactored rewrites tab contents as widget.
Refactored php tab contents as widgets.
Minor refactoring/clean up across the board.
Updated docs.
Added default impl for getVersion().