[Ironruby-core] Sync rubyspec

[Enrico Sada]

I started to update rubyspec to latest version  (pull requests:
https://github.com/IronLanguages/main/pull/35
https://github.com/IronLanguages/main/pull/36 ), the dir
'core/array', 'core/b*' are done.

The rubyspec/rubyspec commit i use as reference is the latest (
https://github.com/rubyspec/rubyspec/commit/ea0ae038fd0e3ab995c44657dbb3f22ef7fa450d
)

At first i tried to branch from a commit 1 year old of
rubyspec/rubyspec, replace branch contents with ironruby's rubyspec
and try to merge to master, but got too much merge conflicts and
merged files not was ok.

So i am merging files in various steps, slower but better quality.

after that i think we can clone rubyspec/rubyspec, branch from commit
ea00ae038 and replace branch contents with ironruby's rubyspec. We get
a clean fork, so more easy to contribute back changes to
rubyspec/rubyspec.