When clearing a linter, be sure to clear the status as well as the marks

Maps one lowercase syntax name to another lowercase syntax name. For example
Use a generic apply_to_all_views method
Added support for syntax map.

Maps one syntax name (lowercase user name) to another syntax name (lowercase).

This led me to copy the existing settings before saving changes, so I can compare the old settings to the new settings in persist.Daemon.settings_updated(), and decide whether a complete relint or just a redraw is necessary.
Text tweaks, small bug fixes and optimizations