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

gemmaimgui/src/bin/support/emmagui_support.rs

@@ -100,6 +100,9 @@ impl GemmaImguiSupport {
         ui.window("!!!! CONTROLS !!!!")
             .size([345.0, 200.0], Condition::FirstUseEver)
             .build(|| {
+                /* System Step Counter */
+                ui.text(format!("Step {:04x}", system_to_control.num_cycles).as_str());
+
                 /* ROM Lister */
                 let new_filename = GuiFileList::display_path(PathBuf::from("resources/roms"), &gui_state.filename_to_load, ui);
                 if !new_filename.is_empty() {
@@ -137,7 +140,7 @@ impl GemmaImguiSupport {
                     *system_to_control = Chip8Computer::new();
                 }
                 if ui.button("Dump Video Memory") {
-                    debug!("{}", system_to_control.dump_video_to_string());
+                    println!("{}", system_to_control.dump_video_to_string());
                 }
                 ui.same_line();
                 if ui.button("Dump Keypad State") {