v0.1.2

Fixed

• On MySQL, which returns JSON objects with their keys sorted, a saved value
  holding an object no longer reads as changed: Save no longer refuses it as
  changed outside the draft, Join reports no conflict for it, a Save records
  no needless batch and Replay recognises the page's digest. MySQL also runs
  in CI.
• The journal's size counts the batches as stored, with their revision and
  author, on MariaDB and MySQL alike, so a draft can no longer pass
  max_draft_bytes and a checkpoint finds the size the updates added up to.
• Field states are written with REPLACE, not MySQL's deprecated VALUES().
• Join builds the page's view once it has released the draft: decoding a
  long journal no longer holds off the draft's appends past their wait (503).
• DraftJournal::saved() and created() take the draft's lock unless their
  caller holds it.
• Saved-view refresh follows saves again once a refused page enters another
  place (collaborate:enter), and keeps the view of the address the page has
  when it refreshes, after a history.pushState.
• Cursors stopped on a layer start again on it, and leave it as they found it.
• A draft session whose form a host removed stops: its replays, listeners and
  hub membership no longer outlive the form, which starts a new session if
  it comes back.
• A peer's event redraws that peer alone: its pointer is measured in the next
  frame rather than as the event comes, the markers and the popup line are
  drawn again only once a peer changes record, popup, name or colour, and a
  caret that did not move is not measured. A frame measures every pointer
  and record before it draws any, looks each region, path and record up once,
  and the layer's announcements and popup lines no longer draw the page again.

Upgrading

• collaborate_draft has an index on updated_at, which the purge reads:
  generate a migration (doctrine:migrations:diff) or add
  CREATE INDEX collaborate_draft_updated_at ON collaborate_draft (updated_at).