Multiple maps print.

* If you include a 'maps' object inside the json spec, it reads layers and srs properties of those and print it with the layout properties configured in the config.yaml.
* A new unit test called 'MapBlockTest' has been added to test it (and the json example spec too)
New parameter for the legends block called 'dontBreakItems'

If you set this flag to 'true', and a new column is added for the legends block, it's don't split legend name and legend image.
Merge pull request #4 from alediator/1_multiple_maps

Multiple maps print.
Merge pull request #5 from alediator/dont_break_legend

New parameter for the legends block called 'dontBreakItems'