We can just make the function accept an arbitrary ProfileManager
reference and operate on that instead of tying the function to the class
itself. This allows us to keep the function internal to the cpp file and
removes the need to forward declare the UUID struct.
These should be initialized to deterministic values so it's easier to
catch improper behavior, as it'll always be reproducable, instead of
performing uninitialized reads.
These are only used within this class, so we can make them private to
keep their use contained. This also gets rid of the pre-Qt5 'slot'
identifier, since Qt 5's connection syntax doesn't require a function to
be declared a slot anymore.
