A field can be required if all his dependencies are validated
remove dead code
Fix bug in case of required with precised dependencies
Fix line lenght
Doc typo fix

ignore_non_values -> ignore_none_values.
This mistake is also present here: http://cerberus.readthedocs.org/en/latest/
Nikita Vlaznev
Merge branch 'NikitaVlaznev-patch-1'
Merge branch 'master' of github.com:hthieu1110/cerberus into hthieu1110-master
DRY and performance for #53
Merge branch 'hthieu1110-master'
Trong Hieu HA
Docs update for #53
Add 'versionchanged' tag.
Merge pull request #54 from girogiro/master

Fix validation of fields with empty definition
Fix validation of fields with empty definition
add `validator` rule for customized function
Docs update for `validator` rule
Improve custom validation docs

Move the _new_types tag back into its appropriate position and reword a few
things here and there.
Luo Peng
New function-based custom validation mode.