Fix switch formatting

The switch cases were not indented and fall-through cases had an
unnecessary additional newline.

Patch by @pscheit (PR #39).

test/code/prettyPrinter/switch.test

@@ -0,0 +1,35 @@
+switch/case/default
+-----
+<?php
+
+switch ($expr) {
+    case 0:
+        echo 'First case, with a break';
+        break;
+    case 1:
+        echo 'Second case, which falls through';
+    case 2:
+    case 3:
+    case 4:
+        echo 'Third case, return instead of break';
+        return;
+    default:
+        echo 'Default case';
+        break;
+}
+-----
+switch ($expr) {
+    case 0:
+        echo 'First case, with a break';
+        break;
+    case 1:
+        echo 'Second case, which falls through';
+    case 2:
+    case 3:
+    case 4:
+        echo 'Third case, return instead of break';
+        return;
+    default:
+        echo 'Default case';
+        break;
+}