valid: add max_length validators
util: move defaults/valid into util module
query: reorder imports
valid: options to alleviate strictness of dict validation
api: use util.valid and util.defaults instead of dispatch_opts
tests/api: test the api level convenience expect function
exceptions: better visual format for ValueIssue
valid: properly rename int_range as range and create convenience validator factories for ints
valid: docs
valid: adding most of the validators needed for django