title: R gWidgets suppress event handler to be triggered when svalue() is used
body: <p>If I change the value of gwidgets object A from another gwidgets object B using svalue(A)&lt;-..., how do I prevent the event handler of object A being triggered? For example, </p>
  
  <pre><code>library(gWidgets)
  window = gwindow("test")
  gg = ggroup(horizontal=TRUE, container=window)
  sb = gspinbutton(value=0, from=0, to=100, by=1, container=gg, handler=function(h,...)print("sb"))
  cbg = gcheckboxgroup(c("geo","ari"), checked=c(TRUE,FALSE), container=gg, handler=function(h,...){
              print("cbg")
              svalue(sb) = svalue(sb) + 1
          })
  </code></pre>
  
  <p>When I check / uncheck the box of "cbg", how do I prevent the event handler of "sb" being triggered? Or, can anyone suggest a better way to do this?</p>