adding support for US military addresses

Added better support for US military addresses and a weighted address
generator.
you're hardcoding `self.address_formats` to a tuple on line 14, so when is this clause ever going to be executed?

Additionally, you're attaching a special meaning to the mutability of the variable that is only known to this method. Without reading the source code, why would I think that a list is a 'weighted_element' and a tuple is not?