Added EncryptedUSSocialSecurityNumberField.
Fixed a type from previous commit.
Fixed typo from last commit.
Merge branch 'master' of github.com:bltravis/django-fields
Updated to use the "cryptographically strong" random from pycrypto library
Enabled backwards compatible support for secure block cipher modes
Changed to get tests to pass.
Merge remote-tracking branch 'kromem/master'

Conflicts:
	src/django_fields/tests.py
Merge branch 'master' of git://github.com/svetlyak40wt/django-fields
Merge pull request #24 from bltravis/master

Added EncryptedUSSocialSecurityNumberField to built-in encrypted fields. (bltravis)
Enabled backwards-compatible support for secure block cipher modes. (kromem)