MIPS Creator CI20 patches (again)

Hello,

I recently looked at the collection of patches accumulated when trying to get 
the CI20 support to a functioning state, and I think I've brought them up to 
date with the latest upstream repository version (r75). In doing so, I've also 
tried to break them up into distinct parcels of functionality so that the less 
interesting or less relevant patches can be ignored.

A page describing the patches can be found here:

http://www.boddie.org.uk/paul/L4Re-Fiasco.OC.html

None of these patches have changed since previous discussions on this topic. 
The rdhwr instruction support I needed to add, for instance, is still done in 
MIPS assembly language, fitting in with existing support for another variant 
of that instruction.

Anyway, I thought it might be useful to put them somewhere with a description 
for future reference. I've yet to get round to looking seriously at L4Re on 
the CI20 again and it isn't likely to happen now before the end of the year.

Paul