Allow users to specify toolbar icons for commands with a backslash. This is in the same style as the replacements made for math-insert commands.

See the user's list:
http://thread.gmane.org/gmane.editors.lyx.general/52712

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@27977 a592a061-630c-0410-9148-cb99ea01b6c8

src/frontends/qt4/GuiApplication.cpp

@@ -319,6 +319,7 @@ QString iconName(FuncRequest const & f, bool unknown)
 		if (!f.argument().empty()) {
 			name1 = name2 + ' ' + toqstr(f.argument());
 			name1.replace(' ', '_');
+			name1.replace('\\', "backslash");
 		}
 	}