Revert "Added warning about serialized object and removed beta."

This reverts commit 260d680cf2d570ca0caa6717147c90526fcc86e0.
Revert "Add generated serialVersionUIDs"

This reverts commit 6120c75d981e8a8b2f84fa6c0950b0a206710dd9.
Revert serializable classes

Although we may want to do this in the future, we first want to figure out
how this relates to our versioning policy and whether we want to do custom
serialization.