adding support for US military addresses

Added better support for US military addresses and a weighted address
generator.
Speed improvements and PEP8
Consistent comments for numerify
change random_weighted_element to dict

Change weighted function to expect a dict, and update the en_US address
list to use random_weighted_element.
move random_weighted_element to random_element
reverting zh_* changes
Merged with HEAD to resolve merge conflict
Using string.ascii_letters for py3 compatibility
Merge branch 'military_address' of https://github.com/bretjb/faker into bretjb-military_address

Conflicts:
	faker/providers/__init__.py
docstring formatting
Improve de_DE providers compliance to Coding Guidelines
Prefer single quotes and added source details
Merge pull request #126 from mdxs/improve_base_provider

Improve base provider
Merge pull request #131 from mdxs/improve_de_DE

Improve de_DE providers
Merge pull request #132 from mdxs/improve_nl_NL

Prefer single quotes and added source details