Mapper improvements

I have improved Annotation Driven Mapper with the following:
 - One annotation `@Map` instead of `@MapExactlyTo` and `@MapNested`. All `@Map `parameters are optional. By default:    
   - `to=...` parameter is set to the same name as the field annotated by `@Map`,   
   - `fromNested=...` is empty,   
   - `of=...` targets all possible classes    
 - `TypeConverter` integration. Multiple converters are included but you can write and register your own easily.

Share your thoughts about my work. :octocat: