Add support to JSON literals, configure property nesting, original sections inclusion and array literal parsing behaviour 

I've added support for enable/disable property nesting, set the behaviour of the array literals (parse json / parse simple arrays / no parse at all) and another useful option to clean up the final array by removing the original pre-inherited sections.

This description for JSON literals can be incluided in the README:

#### Dictionaries and complex structures
Besides arrays, you can create dictionaries and more complex structures using JSON syntax. For example, you can use: 

     staff = '{
        "boss": {
           "name": "John", 
           "age": 42 
        }, 
        "staff": [
           {
              "name": "Mark" 
              "age": 35 
           }, 
           {
              "name": "Bill" 
              "age": 44 
           } 
        ] 
     } '

**NOTE**: Remember to wrap the JSON strings in single quotes for a correct analysis. The JSON names must be enclosed in double quotes and trailing commas are not allowed.