app_server & interface kit: support fill rules.

* BView gets SetFillRule/FillRule methods. The fill rule is part of the
view state.
* The B_NONZERO rule is the default. This is what we implemented before.
* The B_EVEN_ODD rule is the other common possibility for this, and
we need to support it to help WebKit to render properly.

headers/private/app/ServerProtocol.h

@@ -345,6 +345,10 @@ enum {
 	AS_VIEW_SET_TRANSFORM,
 	AS_VIEW_GET_TRANSFORM,
 
+	// Polygon filling rules
+	AS_VIEW_SET_FILL_RULE,
+	AS_VIEW_GET_FILL_RULE,
+
 	AS_LAST_CODE
 };