free move splitter from right to left

- the splitter at the right of the smartlist can moves from left to right
  without constraint.

- the splitter has a width of 10 and a light grey color.

Change-Id: Ib1ed3e3e58ddb3172254ec825694af3afe3cfd8e
Tuleap: #347
diff --git a/callwidget.ui b/callwidget.ui
index 26f4e41..76285e7 100644
--- a/callwidget.ui
+++ b/callwidget.ui
@@ -58,10 +58,10 @@
         <enum>Qt::Horizontal</enum>
        </property>
        <property name="handleWidth">
-        <number>0</number>
+        <number>10</number>
        </property>
        <property name="childrenCollapsible">
-        <bool>false</bool>
+        <bool>true</bool>
        </property>
        <widget class="QWidget" name="widgetSplitterLeft" native="true">
         <property name="sizePolicy">