<bugfix>Fix QChar issue with parameter exploration</bugfix>
<bugfix>Fix QChar issue with parameter exploration</bugfix>

Use unichr instead of QChar.  Note, however, that this looks bizarre on Mac as it shows a large triangle and a small triangle.

vistrails/gui/modules/paramexplore.py:
  - QParameterEditorSelector.__init__: use unichar instead of QChar

hjanime/VisTrails,VisTrails/VisTrails,minesense/VisTrails,hjanime/VisTrails,VisTrails/VisTrails,celiafish/VisTrails,hjanime/VisTrails,VisTrails/VisTrails,VisTrails/VisTrails,Nikea/VisTrails,celiafish/VisTrails,Nikea/VisTrails,minesense/VisTrails,Nikea/VisTrails,celiafish/VisTrails,VisTrails/VisTrails,celiafish/VisTrails,minesense/VisTrails,Nikea/VisTrails,hjanime/VisTrails,minesense/VisTrails,minesense/VisTrails,hjanime/VisTrails