The issue was that batched writing was incorrectly also being applied
for sessionStorage stores, so when the `active` flag in
`_converse.session` was being set to `false` on window unload, the
change wasn't persisted before the window was unloaded.
This caused a new session to be created upon reload, thereby losing the
SMACKS data.
We already solved this for persistent stores by flushing them, and
doing so for the session stores would also work, but session stores
don't have to be batched in the first place, so we turn that off.
If set to a positive integer, the chat history will be kept to that size
by removing older messages.
This happens as new messages come in (as long as the chat isn't scrolled up)
and when the user scrolls down.
Also add the `pruning_behavior` setting
- Update to the latest @converse/skeletor (which uses mergebounce to batch writes)
- Flush storage before logging out
- Flush when reloading the tab
- Create initStorage method
Update storing of app settings. Store settings in a closured
`app_settings` object inside `@converse/headless/shared/settings`
Remove the `_converse.settings` object.
