the simplest fix for a TimeoutException that could possibly work
DownloadUrl should also catch WebException
Fix checking for updates on invalid release file

ParseReleaseFile should handle empty file contents gracefully, and
CheckForUpdate should just return null straight away instead of calling
determineUpdateInfo if there aren't any releases to work with
Add tests for connection issues/blank releases
Add test for DownloadUrl TimeoutException handling

It does take 15 seconds though
Bubble web/timeout exceptions to UpdateManager
Log web/timeout exceptions
Minor checkForUpdate cleanup
Use mock IUrlDownloader for timeout testing
Merge pull request #239 from rzhw/handle-connection-issues

Handle timeout, webexception