Django-luoji-accounts

------------------------------
- New initial mirgations

------------------------------
- added GenericForeignKey and ContentType in TransferManager

------------------------------
- Changed AUDIO to IGET in fixtures

------------------------------
- added fixtures package
- added migrations package

------------------------------
- bugs fixing

------------------------------
- added new field 'user_id' for Account and SunAccount
- changed _validate_user_id method in GeneralAccountManager
- added _validate_merchant_account_user_id in GeneralAccountManager