Converters and Custom Schema parsing

[Rod Widdowson]

As part of the parsing of the ProfileConfigurations, I have worked out how
to get custom schema parsers to listen to Converters.  This allows us to
defer conversion of @Durations and IPRange to Spring and thus allow a
greater space for property replacements.

That is to say that

<Element attribute="${idp.config.duration}"/>

And

idp.config.duration=PT45M

Can be made to "just work" (which they currently do not do for our custom
parsers).

I am not sure, as I type this, whether the attribute resolver or attribute
filters actually have any durations in them, but assuming that they do, do
we think that it is worthwhile to go back and retrofit this (plus tests)?

/R