Creates a PackageItem that contains a desktop icon to be associated with a particular named executable.

Inputs:
Include in package		bool
Symbolic name		QString	The base-name of the icon file.
Destination directory		QString
Source ICO file name		QString
Source ICNS file name		QString
Source PNG files	Array	CSIRO::Package::LinuxDesktopIcon
Outputs:
Package item		CSIRO::Package::PackageItem