User-defined presets for all complex settings

User can make settings, give it a name, and save it as a user-defined preset.

For example, user could create "fast-preview", "medium-preview" and "final render" presets for rendering settings.

These presets can be loaded/saved from HD or internet and be a part of Blender youtube-tutorials. They can be also selected directly from settings tab.

This functionality should be added to all complex settings, like rendering, output, particle systems, node groups, force fields, fluid and smoke simulations, etc. etc.