[Mono-list] ProviderSectionHandler revisited

[Marco Canini]

I attach here a modified versrion of ProviderSectionHandler that solves 
some pbs i had while trying to use mono.data.providerfactory.
A more detailed comment is included in the file header.

I don't send a patch because last time Miguel wasn't able to apply.

I modified ProviderSectionHandler.cs shipped with mcs 0.28

Please commit it to CVS and let Mono.Data.dll be built by default in 
make all.

If you've questions i'm here.