changes to make sc17 preview binaries
the variable will give the GUI a more memorable title than 5.4.1.blahblahblah (once the corresponding change to master goes in).
The data change brings in data with demonstrative materials. Before 5.5 they will most likely be migrated to /plugins/../materials where the app will load them automatically, but for now this is sufficient.
Edited by David E. DeMarle