timed out nodes should be retried


Currently, when a node times out while trying to retrieve its children, it is marked red, and it's impossible to try again fetching this node. as a result, an entire documentation set becomes useless, and I have to download everything again, just because one node failed.

the MSDN web service seems quite unreliable, often returning faults of all sorts. Package This should be able to handle these errors, and allow trying again without throwing exceptions on my face.