Eliminate inefficient slot functions, improves record_consent

Destructive evolution change to most recent evolution, which has not yet
applied in production.
Make html browser use sessions, add/fix slot.records
Add OptionVar.map
Use idents for slot/container.name, add consent

Also fix Truth implicits.
Merge remote-tracking branch 'remotes/origin/master' into angular

Conflicts:
	app/views/widget/panel/browser.scala.html
browser service can set/get item expansion; sort renamed to group