Release Candidate for v1.1.0

@mgorbach @Raizlabs/maintainers-ios 
Please review this at your convenience. Coalesced a few new features into one release.

#### Changes

- Add support for keypaths in custom mappings
- Add capability to ignore keys/keypaths within a dictionary being imported
- Only log a warning for a missing mapping once per key/keypath per object
Good catch - it's fine if it's a set, I just had the type declaration wrong on the param. Fixed.