- Move render_tabs into plinth.views
- Move admin_tabs and user_tabs into the class
- New interproc module contains inter-process functions
- New helper methods in TabMixin
- New class: `MainCfDiagnosis`
- "Advise and repair" mechanism reduces the number of postconf calls
- File locking: lock acquisition moved into audit module
- Enables finer-grained control
- Rewrote action script to eliminate stdin communication
- Changed return type of audit.*.get()
- An audit can return multiple lines of diagnostics
- Move recommended endpoint URLs into function docstrings