Arch: IFC browser - fixes #1384

Arch -> Utilities -> IFC Explorer
This opens a browser window that displays the contents of an IFC file
in a more readable manner than a text editor.

src/Mod/Arch/Resources/Arch.qrc

@@ -40,6 +40,7 @@
         <file>icons/Arch_Rebar_Tree.svg</file>
         <file>icons/Arch_Frame.svg</file>
         <file>icons/Arch_Frame_Tree.svg</file>
+        <file>icons/IFC.svg</file>
         <file>ui/archprefs-base.ui</file>
         <file>ui/archprefs-import.ui</file>
         <file>ui/ParametersWindowDouble.svg</file>