Remove description method from DeclarationOrder

The `description` method is being deprecated.

Change-Id: I27efec67970d21e98a1fe3e8db95d6ff4c23090a
Reviewed-on: http://gerrit.causes.com/36726
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>
Remove description method from abstract Linter

We don't want linter subclasses to be implementing this method as a
means of defining a default message, since it somewhat obfuscates where
the message comes from.

Remove it now that all references to `description` have been removed.

Change-Id: I0360927b3e72067136654d177980a4ee279fb8d0
Reviewed-on: http://gerrit.causes.com/36727
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>