Remove containerd specific parts of the plugin package to prepare its
move out of the main repository. Separate the plugin registration
singleton into a separate package.
Separating out the plugin package and registration makes it easier to
implement external plugins without creating a dependency loop.
Signed-off-by: Derek McGowan <derek@mcg.dev>
The plugins packages defines the plugins used by containerd.
Move all the types and properties to this package.
Signed-off-by: Derek McGowan <derek@mcg.dev>
Add garbage collection as a background process and policy
configuration for configuring when to run garbage collection.
By default garbage collection will run when deletion occurs
and no more than 20ms out of every second.
Signed-off-by: Derek McGowan <derek@mcgstyle.net>