split sass sheets, move style cascades

src/Bundle/ChillMainBundle/Resources/public/chill/scss/render_box.scss

@@ -0,0 +1,13 @@
+// generic rules
+section.chill-entity {
+
+    // display inline for render raw
+    // have no effect for render label, row, bloc !
+    display: inline;
+
+    // don't break flex cascade with section tag
+    div.flex-bloc & {
+        display: flex;
+        flex-grow: 1; flex-shrink: 1; flex-basis: auto;
+    }
+}