Add PHP dependency and filter format

## Ready State: Yes

This will automate the following:

1. Enabling PHP module
2. Creating PHP code filter 

## Requirements & Dependencies

* None

## Deployment Instructions

* Merge code.
* Enable module `imagex_widgets_code`: `drush en imagex_widgets_code`
* Clear caches with `drush cache-clear all`

## Usage/Test Instructions

* Verify that PHP filter module is enabled
* Verify that PHP filter is available with php code enabled