Authority check rule change

- New user type created
	METIC 	: Can read anything but no privilege to create nor delete
	YEOMAN	: Can read and create, delete anything
	ADMIN	: User has any authority. Can access administrator page.
	SUPER	: This stands for Django administrator user.
- authority check gets faster slightly. check purposed type of authority
only and ignore other types. For example, If it is checking for writing
authority, reading and deleting authority won't be checked and it always
returns true.