[FIX] Hack css for graph view

The best way will be to set svg height, but IE9 does not understand height="xxx". So we override the overflow set by bootstrap.css to fix it.

bzr revid: jke@openerp.com-20140318150059-nd6bdd58uvr1s4um

addons/web_graph/static/src/css/graph.css

@@ -1,3 +1,11 @@
+ /* 
+ This is a hack for IE9 ...
+ Attrs : width and height are not take in consideration
+ */
+.openerp svg:not(:root) {
+    overflow: visible;    
+}
+
 .graph_pivot_mode {
     position:initial;
 }