This is a bit involved because since the LinkTarget now creates the
instdir/sdk/lib/* files itself a Package cannot be used; so convert the
URE libraries to AutoInstall and add special handling for them to
gb_Helper_register_libraries_for_install to create the necessary links
in the "sdk" install-module.

(regression from 70c35265)

Change-Id: Ia5467f3303d59f7f5f4a88adc22ceffb82a21ff1