title: Porting Qt5 app to Qt4
body: <p>Yes the title is correct...we are going BACK to qt4.  We recently built a decent size app with Qt5.  We now been told that the app must support RH 6 and RH 5 distros.</p>
  
  <p>Since RH6 ships with Qt 4.6.2 and Rh 5 ships with Qt 3.3.6, I'm concerned about having to make lots of modifications to port back to older versions of Qt.</p>
  
  <p>Can the latest versionf of Qt 4.x and 3.x understand new syntax of Qt5 (eg: connect is slightly different)?  If not, can someone suggest how best to undertake this?  Are we looking at ifdef'ing our way out of this?  (and if so, is there an easy reference for how to do this)</p>