Set windows package install directory to "Displaz"

This seems a bit more in keeping with other windows installers, and has
the side effect of fixing the automatic uninstall step in the future, to
automatically uninstall older versions of displaz (see also
CPACK_PACKAGE_INSTALL_REGISTRY_KEY).

CMakeLists.txt

@@ -196,6 +196,7 @@ set(CPACK_PACKAGE_DESCRIPTION_SUMMARY "A viewer for geospatial lidar data")
 set(CPACK_PACKAGE_DESCRIPTION_FILE "${PROJECT_SOURCE_DIR}/README.rst")
 set(CPACK_RESOURCE_FILE_README "${PROJECT_SOURCE_DIR}/README.rst")
 set(CPACK_RESOURCE_FILE_LICENSE "${PROJECT_SOURCE_DIR}/LICENSE.txt")
+set(CPACK_PACKAGE_INSTALL_DIRECTORY "Displaz")
 if (WIN32)
     # Some paths need at at least one backslash to workaround NSIS bug
     set(CPACK_PACKAGE_ICON "${CMAKE_SOURCE_DIR}/package\\\\displaz.ico")