Removed obsolete info in documentation.

Generating client secret on every save() was removed in 5a6bd052.
Merge pull request #1 from EE/docs-fix

Removed obsolete info in documentation.
Added blank=True to auto-generated fields.

This fixes validation problem with creating new model instances in admin.
Added handling of non-integer client_id parameter in views.
Fixed improper exception description.
Merge pull request #2 from EE/secret-generation

Added blank=True to auto-generated fields.
Merge pull request #3 from EE/client-validation

Added handling of non-integer client_id parameter in views.
Merge pull request #4 from EE/exception-description

Fixed improper exception description.