MIRTH-3208: Fixed issue that caused NPEs when deploying channels. Because retrieving dashboard statuses isn't synchronized with actual deploys/undeploys, we need to check that a channel is still deployed before actually adding a status for it.
MIRTH-3202: Improved how channels are retrieved in the Channels view. Instead of making two different requests to get the channel summaries and the channels themselves, the client is now only making one request, and the server sends back any information the client needs to update. ChannelSummary now contains a new ChannelStatus object, which includes the Channel itself, as well as the deployed date and revision delta. Back in the client, instead of a cache of Channel objects, it's now holding a cache of ChannelStatus objects, so that it can persist the deployed channel information in the same place.