Fix bugs in Map

If a region is added that is already in the regions dictionary, an
exception is thrown. This can be prevented with a quick check if
the region's id is already a key in the dictionary.

And if you add an continent, its regions get added to the map's
dictionary of regions as well.
Change template for new files

The standard header is now inherited from project's solution. This
should be a better behavior with multiple autors (and therefore
multiple headers).