Add clang-format file

Also run it across the whole tree to get everything using the One True Style.
We don't yet run this in an automated fashion as it's a little slow, but
there is a snippet to do so in makeall.sh.

DevTools/VisualBuilder/VBWidgetPropertyModel.h

@@ -7,7 +7,8 @@ class VBProperty;
 
 class VBWidgetPropertyModel : public GModel {
 public:
-    enum Column {
+    enum Column
+    {
         Name = 0,
         Value,
         __Count