title: PyCharm 4 wont open Qt Designer on double click of .ui file. (Linux)
body: <p>PyCharm and Qt Designer are both installed and running.  PyCharm shows .ui files as Qt designer files, but nothing happens when I click on them, or double click on them.  In order to edit them, I have to right click --> show in open folder with Thunar [I'm on Xfce] and then double click the file from the file manager which will open it in Qt Designer.</p>
  
  <p>I dont see any options in the settings for changing this behavior.  Any ideas on how to make Qt Designer get launched from PyCharm?</p>