VC8E emulation for PDP-8

[philbudne]

Note: there is an old (closed) issue for this at #337

I didn't know if commenting there would be noticed, so I've created a new issue. Feel free to merge into the old issue.

I'm the original author of the X-Y display code in SimH which I had based Douglas Jones PDP-8 Emulator w/ VC8E support, and have always meant to go back and add PDP-8 display support.

Previously the only version of spacewar for the PDP-8 was for the LAB8, but I found a version that was modified for the VC8E.

My changes are at https://github.com/philbudne/simh/tree/vc8e

The branch contains binary and .ini files for the modified spacewar, and a kaleidoscope program (from DEC's small computer handbook) in the PDP8/vc8e/ directory. (Just realized I didn't make sure the source and .ini files in this directory contain CRLF line termination).

I'm sure there is plenty that could be reviewed/discussed about my changes, but thought I'd open an issue before dropping a P.R. with my first draft of the code.