GravityView - DataTables Extension 3.3.6

* Added: Auto-Update setting! DataTables will automatically refresh with new entries as they're added. [Learn more about the new Auto-Update feature!](https://docs.gravityview.co/article/821-enable-auto-update-datatables-setting)
- You control how frequently the data refreshes. By default, it's every 5 minutes.

* Fixed: DataTables scripts would not load when manually outputting the contents of the `[gravityview]` shortcode. Requires GravityView 2.13.4 or newer.

* Fixed: GravityView Entry Approval not working when in responsive mode (requires GravityView 2.13.2 or newer)
* Fixed: Images displayed in a lightbox were duplicated when in responsive mode
* Fixed: Searching while FixedColumns breaks the table layout
* Fixed: DataTables scripts were being enqueued on every page load
* Fixed: DataTables scripts were enqueued on every page load
* Fixed: The field setting "Custom CSS Class" was not being used in the output
* Improved: Minor security fix

__Developer Updates:__

* Modified: Changed enqueuing of scripts to happen from the `gravityview/template/after` action
* This means GravityView 1.x template overrides will no longer function for DataTables. See our [template migration guide](https://github.com/gravityview/GravityView/wiki/Template-Migration) for more information.
* Modified: Removed support for exporting using deprecated .swf behavior in DataTables
* Modified: Removed use of global `gvDTButtons` JavaScript variable on the front-end