Re-added VT100 test that was created for KIPPERTERM development. Not very usefully as-is but a good template for any offline VT100 rendering test/debugging.
Additionally the disk images were renamed to distinguish them from the disk images created in the apps directory.
- Simplify Makefile by allowing to use suffix '_tcp' to denote the requirement to link against TCP-capable IP65 lib.
- Remove 'test' or 'test_' prefix from test program names - every program in 'test' is a test program.
- Have some more test programs switch to lower case charset on the C64.
- I'm no Ruby guy so don't rely on Ruby for building disk images.
