[ohm] New additions to wiki

[Rob Taylor]

I've been in Finland today brainstorming to get more detail on OHM with
some of the Nokia guys and Nils Faerber. The wiki now has an added
section with a (pretty exhaustive) list of possible inputs and outputs
of OHM [1], and a new set of detailed usecases [2], referencing these.

All criticism/feedback appreciated!

Thanks,
Rob Taylor

[1] http://ohm.freedesktop.org/wiki/InputOutputs
[2] http://ohm.freedesktop.org/wiki/UseCases