Add localized support for social security number or equivalent

Localization of US social security number and Canadian Social insurance
number.
Update Canada SSN/SIN provider to create a valid number

The first revision generated a random number in the correct format.
This commit creates a SIN number that passes the checksum as described
here http://http://en.wikipedia.org/wiki/Social_Insurance_Number
Merge branch 'master' of https://github.com/milliquet/faker into milliquet-master

Conflicts:
	faker/__init__.py