improve mobile login,home and settings styles

demo-shell-ng2/app/components/setting/setting.component.html

@@ -24,6 +24,11 @@
                            tabindex="1" (change)="onChangeBPMHost($event)" value="{{bpmHost}}"/>
                 </nav>
             </div>
+            <div class="mdl-card__actions mdl-card--border">
+            <a class="mdl-button mdl-button--colored mdl-js-button mdl-js-ripple-effect" onclick="window.history.back()" >
+                Back
+            </a>
+        </div>
         </div>
         <div class="setting-card-padding"></div>
     </div>