Added left panel rom loader.

Left panel has tinyfieldialogs to open a file picker, so you can swap
out roms, required a reset machine function aswell.

src/machine/machine.odin

@@ -68,3 +68,18 @@ run_machine :: proc(s: ^System, cycles: int) {
 		cycle(s)
 	}
 }
+
+new_machine :: proc() -> System {
+    s: System
+    s.pc = 0x200
+    s.current_key = -1
+	// load fonts into the memory
+	for v, i in FONT_SET {
+		s.memory[i] = v
+	}
+    return s
+}
+
+reset_machine :: proc(s: ^System) {
+    s^ = new_machine()
+}