More int type fixes and tests for drivers

Just pulled in nightly and got a whole bunch of errors like this:
```
error: cannot determine a type for this expression: cannot determine the type of this integer; add a suffix to specify the type explicitly
```

Not sure, may be this just a follow-up on rust-lang/rust#6023?
diff --git a/src/drivers/lcd/mod.rs b/src/drivers/lcd/mod.rs
index c8992ad..ba60962 100644
--- a/src/drivers/lcd/mod.rs
+++ b/src/drivers/lcd/mod.rs
@@ -306,6 +306,13 @@ mod test {
       assert!(v == diagonal[x as uint][y as uint]);
     });
 
+    io.line(15, 15, 0, 0, 1);
+
+    //io.for_each(|(x, y), v| {
+    //  assert!(v == diagonal[y as uint][x as uint]);
+    //  assert!(v == diagonal[x as uint][y as uint]);
+    //});
+
     io.clear();
 
     let non_symetric: [[u16, ..16], ..16] = [