Adding S3 objects

And other smaller updates

Adding stream-network features

Adding options to allow VAST to use stream-network model, including code to demonstrate feature and conduct integrated-testing for backwards compatibility, h/t Merrill Rudd for implementing and testing options

Adding features for `fine_scale=TRUE`

2.0.0

Adding features for `fine_scale=TRUE`

Initial release

Package containing data and code dependencies for SpatialDeltaGLMM (which is now deprecated), VAST, and MIST (which is also now deprecated)