To set the list of feeds to be managed by the pool.
The previous list, if any, is invalidated. After invokation to the function,
@switch must be call to run the auto-fetching (always, also if previous state was "running"). The list in feeds can be
freed after calling this; linked FeedChannel are g_object_ref'd here.
| this |
a FeedsPool. |
| feeds |
a list of FeedChannel. |