Merge pull request #1 from mobilejazz/master

Update from mobilejazz:master
Reduce code
Use return value of automatic validation
Only return YES if transformed value is not nil
NSString to NSDate automatic validation
mjz_didCreateObject:forKey. TODO: Move to delegate?
NSString -> BOOL
Bug fix
Merge pull request #4 from robotmedia/master

Improvements
Bug in MJVideo array mapping
Merge conflicts
Fixing bugs. Improving method names. Adding new method for automatic validation object creation
Merge branch 'master' into development