more validation tests for gemma video rendering

Adds 'doom like' 3dviprmaze-vip for demo (VERY VERY SLOW)
updates egui interface to let user select from files in resources/roms
updates cargo to centralize dependencies
95 passing tests

gemmatelnet/src/bin/gemmatelnetd.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Taxation is Theft");
+}