Ignoring a lot of stuff in gitignore now
Fixes issue #3 - adds the ability to remove test cases based on date/release/test ID. Also updated CSVReader to 2.3.0.
Fixes issue #2 - Adds functionality to RenderlyApp to update the reference image for test cases by test case ID. The app will download the source (basically the remote image used for comparison) and replace the reference image with it. Also moved Rendering.Options namespace to Rendering.Commands since the app is now multi-command.
Fixes issue #4 - adds functionality to RenderlyApp to allow filtering of test cases to run by TestId, Date, and Release. Made command options consistent across commands so 'd' doesn't mean DataSource in the RunRenderingCommand anymore, and cleaned up code around using PredicateBuilder by defaulting all IEnumerable sequences to Enumerable.Empty<T> so I don't have to use null checks everywhere.