v7.0-beta.80

* Issue **#2018** : Fixed intermittent search issue that was sometimes causing search to complete too early without results.

* Fix dashboards not handling NUMERIC index fields.

* Fix bug in Negate expression function.

* Issue **#1995** : Add help info to the expression functions drop down menu.

* Issue **#1911** : Add a drop down menu for picking index fields in the expression editor.

* Issue **#2004** : Fix import of legacy v6 index so default volume group is assigned.

* Issue **#2017** : Fixed dashboard table filtering.

* Issue **#1946** : Removed unnecessary index shard state change error.