revert last commit, sawyer.Response doesn't have pointer to sawyer.Request
cache rels after decoding resource
noOp cacher singleton
unused interface
attempt to cache the rels on a CachedResource
cache functions that return rels also return a bool showing the status
fully document sawyer, move some types around
the mediatype package configures its own default encoders and decoders
change the httpcache Get() to return the cached response

this object will let us deal with expiration better
unused helper
update cache expiration from a 304
more httpcache docs
add client.Rels()