Added event type cache tags to date explain controller for when event type date configuration changes.

Must use RNG-dev (rc4+) or RNG-rc5

Requires strict type checks as FALSE and NULL are both valid.

Added documentation for event date provider injection in DateExplain controller.

Simplify .module, moved helper function to new event date provider service.
Added max age cache setting to date explain controller to fix non-final date cache persistence.

Renamed render array variable.

Improved module description.
Added dependency to datetime.module
Improved README.
Fixed indentation in .module.

fixed some caching
fixed forbidden after last time slot.

Working, but needs work.
Only works with datetime (not date-only) fields. Despite what the UI says.