Can only pause first variation

[atwellpub]

http://support.inboundnow.com/support/topic/cannot-see-status-summaries-for-landing-pages/

Addresses:

• Variation A Cannot Pause
• Wrong stats are trashed when variation trashed.
• Correct stats and letters show on both landing page listing page and landing page quick stats metabox in landing page edit screen.
• Adds upgrade routine to change original variation meta key for variation notes and variation status (see https://github.com/inboundnow/landing-pages/blob/develop/classes/class.activation.upgrade-routines.php#L216-L244)