Detect when WP-Cron is disabled.

[octalmage]

Since the plugin relies on WP-Cron, we should detect when it's disabled and show a notice.

It can be disabled using a define:

define( 'DISABLE_WP_CRON', true );

[Pross]

A lot of people disable it in config then have a crontab on the server to load wp-cron.php?doing_wp_cron once per minute.

[octalmage]

That's a good point, we actually do this at WP Engine. Hmmm.

[octalmage]

I'm seeing this come up a lot, I think it wouldn't hurt to give a small notice about the DISABLE_WP_CRON define incase it is causing issues.