Expand KALITE_SCRIPT_DIR properly when creating startup task
Expand KALITE_SCRIPT_DIR properly when creating startup task

Don't use the external script, which relies on the expansion of
KALITE_SCRIPT_DIR -- the env won't be updated until *after* the
installer exits, so the scheduled task will be misconfigured.

In the installer, create the task from the cmd line and fetch
KALITE_SCRIPT_DIR directly from the registry.

learningequality/installers,ruimalheiro/installers,learningequality/installers,learningequality/ka-lite-installers,learningequality/ka-lite-installers,benjaoming/installers,benjaoming/installers,learningequality/ka-lite-installers,benjaoming/installers,learningequality/installers,mrpau/installers,benjaoming/installers,learningequality/ka-lite-installers,learningequality/installers,mrpau/installers,ruimalheiro/installers,mrpau/installers,ruimalheiro/installers,ruimalheiro/installers,mrpau/installers