unpegged version
added deletion tests
added pickle support for models (TPCK-53)
cleaned up cache test a bit
added options to resources
streamlined Base.exists, and caching.  Added resource-based cache options support
updated changes
targeting 1.5.0 release
decomposed base class into a bunch of concerns.  Laid the foundation of EmbeddedBase
don't add validators to classes that aren't validatable
fixed a bug with serializing
renamed evictable to cacheable, and improved cache decorator robustness
added specific methods for fetching an attribute vs an association, which getattr delegates to
added SingleEmbeddedAssociation and EmbeddedResource
did a bunch of unification between single association and single embedded
added a default optional arg to HasAttributes._get_attribute
removed data_queryify, and more streamlining
fixed typo
added embedded associations.  cleaned up association code a little more
updated changes