So that it persists across page loads. Otherwise storage falls back to
the default, causing records to be in both local- and sessionStorage.

Additionally, update singleton models to have the 'id' available as a getter.

Otherwise multiple records gets stored in browserStorage, causing random
results being returned.

Also remove Converse from fullscreen background

Also fixes #1153

Fixes #1154

Which meant that occupants were being duplicated.

updates #1146