Writes the configuration to disk.

def write(self, parallel=True):
        """
        Writes the configuration to disk.
        """
        # Write the Solution files
        solutions = sorted(self._solutions, key=lambda x: x.Name)
        with VSGWriteCommand('Writing VSG Solution', solutions, parallel) as command:
            command.execute()

        # Write the Projects files
        projects = set(sorted((p for s in solutions for p in s.Projects), key=lambda x: x.Name))
        with VSGWriteCommand('Writing VSG Projects', projects, parallel) as command:
            command.execute()

        # Register the registerables
        registerables = set(sorted((p for s in solutions for p in s.Projects), key=lambda x: x.Name))
        with VSGRegisterCommand('Registering Project Registerables', registerables) as command:
            command.execute()