ikiwiki/ todo/ smileys do not work in PreprocessorDirective arguments

Several PreprocessorDirectives take ikiwiki-formatted text as arguments, such as the then and else arguments of the new if directive, or the desc argument of the shortcut directive. However, smileys do not work in these arguments.

Since the arguments to PreprocessorDirectives might use the same syntax as smileys for a different meaning, smiley substitution should not happen until after PreprocessorDirectives.

--JoshTriplett

Sorry, I should have filed this under bugs, not todo.

Also, for an example of this issue, consider the sample conditional on conditional.

--JoshTriplett

done --Joey