public interface Preset
This interface offers methods to query and manipulate parameter preset sets.
A preset is a bunch of property settings, together with meta data and a name. The name of a preset serves as key for subsequent method calls
to manipulate single presets. All instances of one type will share the list of presets. The list is created on demand, if presets are not used,
the list is not created.
The interface comes with a default implementation that serves most plugins. Wrapper plugins will override most methods to implement support for
the native preset format of those wrapped plugins. One method that is useful to be overridden is
get_property_names. With that one can control which
properties are saved and in which order.
The default implementation supports presets located in a system directory, application specific directory and in the users home directory. When
getting a list of presets individual presets are read and overlaid in 1) system, 2) application and 3) user order. Whenever an earlier entry is
newer, the later entries will be updated.