1. when no applet is involed:
   + guigen.xml.co (CommandObject) from src/main/conf/ is used in RunServiceApp()

2. when applet is involed:
   + guigen.xml in src/main/conf/ is used to render the applet;
   + the updated guigen.xml (CommandObject, already converted) is saved in
     result/tool/_guigen.xml

3. When a tool is selected to run, the -DtoolFile is selected as follows: 
   + check result/tool/ directory if  _guigen.xml exists, if yes, use it
   + otherwise, get it from src/main/resources/conf/guigen.xml.co