Formatter interface definition

First definition of the interface of the Formatter package.
Makefile is complete, too, although it just builds an
empty test.

Signed-off-by: Raffaele Aquilone <raquiloX>
FormatterManager and first version of ConsoleFunctor implemented

Implemented FormatterManager and the ConsoleFunctor, although
format has to be revised because it's pretty ugly right now.

Signed-off-by: Raffaele Aquilone <aquiloneraf@gmail.com>
TXT and CSV Functors completed and tested

Both the TxtFunctor and the CsvFunctor have been completed and
tested, and a new header file for utils has been introduced.

Signed-off-by: Raffaele Aquilone <aquiloneraf@gmail.com>
JSON functor completed and tested

Completed JSON functor and fixed some minor issue in other
functors.

Signed-off-by: Raffaele Aquilone <aquiloneraf@gmail.com>
XML functor completed and tested

Now all functors have been completed and tested

Signed-off-by: Raffaele Aquilone <aquiloneraf@gmail.com>
Fixed missing XML header

Added missing XML header, now the XML Functor works fine

Signed-off-by: Raffaele Aquilone <aquiloneraf@gmail.com>
Merge branch 'formatter_dev' into formatter
Merge branch 'formatter' into develop