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

[Alistair Bush]

> > Yes, we shouldn't have any .cs files that are not included in any
> > .csproj. I would be surprised if there were too many of them but there
> > might be some. Feel free to send a patch that deletes them.
> > 

see here https://github.com/alistair/ironruby/tree/cleanup  

the cleanup commit directly

https://github.com/alistair/ironruby/commit/7ea7f14c6f91e22ca3ee4a608499b7dfd5523c28


> 
> So....
> 
> Question 1:   Microsoft.Scripting.Core.csproj contains a "reference"
> (<Content>) to System.Linq.Expressions.txt which is not located within the
> repository.   Im assuming this is safe to remove?
> 

I assumed this was to be removed and have committed it into the above branch. 
[1] I also added build.sh files within that branch that just document the 
xbuild commands I used to test compile.  That commit can be safely ignored 
(and probably should be).  I only tested the Runtime directory projects and 
only with Debug config.   But im pretty confident it shouldn't have broken the 
Silverlight builds.


[1] 
https://github.com/alistair/ironruby/commit/8c348784a865080fef27e6ce668f02548d6b1722