Windows installer: append the package version to registry

On installation, set the "DisplayVersion" registry value
to ${SUBSURFACE_VERSION}, so that a version is displayed
when browsing the list of installed programs.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>