add io brick, misc fixes

bricks/execall.cs

@@ -12,6 +12,7 @@ exec("./gates/srlatch.cs");
 exec("./inputs/switch.cs");
 exec("./inputs/button.cs");
 exec("./inputs/keyboard.cs");
+exec("./inputs/iobrick.cs");
 
 exec("./math/8bitAdder.cs");
 exec("./math/8bitSubtractor.cs");
@@ -22,6 +23,7 @@ exec("./math/HalfAdder.cs");
 
 exec("./outputs/Pixel3.cs");
 exec("./outputs/TextBrick2.cs");
+exec("./outputs/Pixel2x2.cs");
 
 exec("./special/EventGate.cs");
 exec("./special/rom.cs");