Added a fixed height for resourcesload watermark

Currently there was no block with hidden overflow so timetracker was making the scrollable
area grow vertically in an excesive proportion, making the scroll unusable. This workaround
gives a more reasonable amount of space untill is not calculated dinamically.

FEA: ItEr75S04BugFixing

ganttzk/src/main/resources/web/ganttz/zul/timetracker/timetrackersecondlevel.zul

@@ -20,7 +20,7 @@
 -->
 
 <zk xmlns:n="http://www.zkoss.org/2005/zk/native">
-    <n:div class="z-grid-header">
+    <n:div class="z-grid-header timetracker-secondlevel">
         <n:table style="width: ${top.horizontalSize-2}px;" class="second_level_">
 
             <n:tr class="z-columns">
@@ -39,4 +39,4 @@
             </n:tr>
         </n:table>
     </n:div>
-</zk>
+</zk>

navalplanner-webapp/src/main/webapp/common/css/navalplan_zk.css

@@ -1128,8 +1128,8 @@ tr.z-treerow-seld {
     overflow:hidden;
  }
 
-.resourcesload .timetrackergap .z-grid-header{
-    heigth: 15px;
+.resourcesload .timetracker-secondlevel {
+    height: 2000px;
 }
 
 .scheduling-graphics .z-tabs-ver {