This component provides generic way for components and their extensions to check for updates.

From user perspective, 'generic' means that their list in consolidated in one place in preferences, and single UI element can be used to get notifications about all updates.

From developer perspective it means that all common work, needed to provide checking for updates, scheduling auto check and caching results, is already done and does not need to be reimplemented.

This component does not supersede standard foobar2000 way to check for updates but may complement it.

foo_acfu in UI