Returns the path to the Softimage installation directory, the current user directory
and other useful paths. This makes it possible to write scripts that do not
rely on hardcoded paths and which work on any user's machine.
The returned paths do not include a trailing path separator character.
Note: In the case of multiple workgroups this method returns only the
first workgroup (when called with siWorkgroupPath or siWorkgroupAddonPath).
The best way to retrieve the full list of active workgroups is via
XSIApplication.Workgroups.
Note: This is the Python-compliant version of XSIApplication.InstallationPath.
Since Python does not support input parameters on properties, XSIApplication.InstallationPath
will fail in Python.