v0.7.8

Added

• Toolkit\Lock and LockTimeout: exclusive file locks that serialize work across PHP processes on one host. App::lock($key, $fn, $timeout) is the keyed entry point. It is re-entrant, and unrelated keys share a fixed set of lock files.
• Request::files($key) returns the uploads for a key as a list of single-file entries, for name="file" and name="file[]" alike.
• Multi-file upload in the admin Files tab, with a progress bar while it runs. A failed file is reported by name.
• The edit panel keeps its open tab in the session.

Changed

• Record::save() runs under $app->lock(), keyed by the record's registry key, and merges against what is on disk when the lock is taken. Concurrent saves of different fields on one record all land. A read-then-write of the same field, such as a counter, needs the caller's own $app->lock().
• Item::delete() takes the same lock.