Ironruby core - Aug 2011 - Pull Request #29 - Sync with rubyspec/mspec

I am implementing IO#binread for workitem 6345
(http://ironruby.codeplex.com/workitem/6345).

The rubyspec for IO#binread is missing, so i added it with pull
request to rubyspec/rubyspec ( these are my first contributions so i
want to have feedback about how to write rubyspec ).

Now rubyspec and mspec are added to ironruby repo, so someone need
mantain it and send the changes to rubyspec/rubyspec.

I think we can use submodules for that, one for rubyspec and one for mspec.
The submodules are in the old rubyspec and mspec directories, so nothing change.

There are some advantage:

- we can directly commit to rubyspec/rubyspec and let rubyspec authors
manage changes
- easy to update and test new rubyspec versions (stable or head)

Using an IronLanguages/rubyspec clone as submodule we have the same
workflow we have now (ironruby contrib send rubyspec change to
IronLanguages/rubyspec and after ironruby send these to
rubyspec/rubyspec )

My pull request link submodules to my personal rubyspec clone
(enricosada/rubyspec)