Remove DEFAULT_PERMISSION_CLASS in lieu of view inheritence.
Remove DEFAULT_PERMISSION_CLASS in lieu of view inheritence.

       * Moving to an inheritence model makes it easier to address future changes
       in DRF quickly.
       * We were using DRF built-ins instead of our own permissions classes. Our own
       permissions have slightly different behavior.
       * Defaults won't work because there are too many special cases.

	modified:   atmosphere/settings/__init__.py

CCI-MOC/GUI-Backend,CCI-MOC/GUI-Backend,CCI-MOC/GUI-Backend,CCI-MOC/GUI-Backend