[Ironruby-core] Cleaning up of the Source Tree - Removal of Redundant files

[Alistair Bush]

As ive already mentioned there are currently (within Runtime at least) a large 
number of *.cs files that are not included in any csproj files.  These files seem 
to implement classes that already exist within System.* dll's.

There also seem to be some *Build*csproj files.  Are these maintained?  If not, 
we should clean them up as well.

Are we able to clean up all those redundant files please.  I will provide a 
patch during the weekend for it but currently im only looking at DLR (that the 
patch will only cover Runtime/*)

Could we also introduce a policy that in future if we remove a file from a 
project it also gets deleted (assuming you are removing it from all projects).

Thanks

Alistair.