The currently implementation of install/uninstall/launch etc. are not for Tizen wgt package but for crosswalk XPK package. The Tizen legacy support is under way and may redactor the code heavly, like introducing some abstractions and separate the back-end support for different package formats.
I know the current code may look a bit weird and confusing: Code the 'tizen' folder are used to accommodate to the Tizen system requirements for crosswalk packages.
So would you please change the name to something else, like InstallPackageOnTizen.