Add render_getConfOption.sh function to standardize the way options
    are retrived from pre-rendering configuration files. 
    
        - Update related files to retrive options from pre-rendering
          configuration files using render_getConfOption function.
    
    Update render_doIdentityImageGdm.sh to create both gdm and kdm tar.gz
    theme files. 
    
        - Remove build-targz.sh files from from rendering configuration
          structure. Use render_doIdentityImageGdm.sh instead.  
    
        - Update both gdm and kdm pre-rendering configuration scripts to
          start using render_doIdentityImageGdm.sh. 
    
        - Rename render_doIdentityImageGdm function definition to
          render_doIdentityImageDm.