Start using positional decorator

Apply the positional decorator to functions. It has been added as I
think best practice would dictate, though in some places it has been
added in a way that doesn't break existing tests.

Closes-Bug: #1295881
Change-Id: I4f7ddbede4cba4ab79d144ad1f9dc83ea76f204a
Merge "Start using positional decorator"
Test commit