LDC-536 Feature imagex_events, add field event_date, remove field_date

## Ready State: Yes

Feature imagex_events, add field event_date, remove field_date.

## Requirements & Dependencies

* Requires pull https://github.com/imagex/linux.com/pull/321

## Deployment Instructions

* Merge code.
* admin/structure/features/imagex_events -> Revert components or `drush fr imagex_events `
* Clear caches with `drush cache-clear all`