- adds the new column to the DB table.
- data stored in the DB is encrypted
- update appRouteHeaders templates to use the jsonData and
decrypted secureJsonData

Fix dashboard sorting in playlists

add export to csv in table panel

ApiPlugin custom header support

The header content uses text/Template.  If the apiPlugin is
bundled in an App, then the appSettings.JsonData is passed
to the header template.

allow saving changes to appModel made by configView directive

configView directives can update the appModel object.  We need
a save button to persist the updates.

(prometheus) add explanation about incompatibility of metric find query

Removed unused component from playlist code

get apiPlugins working again.