Porting ejpi: Icon Theming

ejpi includes some custom icons as well as using theme icons.

The custom icons are used for a couple of buttons.  I know the path to the custom icons and I load them up and everything works as expected.

The stock icons are used for deleting items in the calculator's history as well as a severity indicator and close button for the error info box.

I ported the GTK code from using theme icon names to QIcon.fromTheme.  It was fun for me to find out that fromTheme was added in Qt 4.6 (I still support Maemo 4.1 with my applications and it only has Qt 4.2 I think).  How did applications do this before 4.6?  I don't think I've used KDE since v2 but I think its generally supported icon theming along with everything else which precludes the application building all icons in as resources.

I also had fun with fd.o icon names not being available on all platforms so I had to find alternatives for each and put in fallback code.

I guess chock this up as another thing to abstract away when running on various platforms.

I'm not saying this was hard or anything but just another lessons learned in porting to Qt.