Updated rubygems to 2.0.6.
Merge remote-tracking branch 'origin/master' into compiler
Merge pull request #2500 from kachick/2.0-kernel-warn

Kernel.#warn should accept multiple messages as Kernel.#puts from 2.0
Write specs for String#b

* https://github.com/rubinius/rubinius/pull/2501#pullrequestreviewcomment-5416650
* https://github.com/rubinius/rubinius/pull/2501#pullrequestreviewcomment-5416641
* https://github.com/rubinius/rubinius/pull/2501#pullrequestreviewcomment-5431863
Implement String#b
Fix a spec fixture for Marshal on BasicObject

https://github.com/rubinius/rubinius/pull/2503#pullrequestreviewcomment-5437588
Fix Marshal with BasicObject
Merge pull request #2503 from kachick/fix-marshal-basicobject

Fix Marshal with BasicObject
Merge pull request #2501 from kachick/2.0-string-b

Implement String#b for 2.0
More build tools.
Add better handling for IncludedModule to vm debug method
Add spec for calling super from toplevel module
Add spec for prepending into existing module chain
Add specs on Kernel#eval with local variables in the same binding.
Improve spec for prepending multiple modules by going through chain
Fix lookup start for super calls when prepending
Tag failing prepend specs for now
Merge remote-tracking branch 'origin/master' into compiler

Conflicts:
	kernel/common/string20.rb
Rework Module#prepend and origin logic

This switches to a different mechanism to fix some issues with
Module#prepend exposed by previously added specs.

The problem was mostly wrong ordering and prepending into already
included modules into other classes. The first problem was solved by
actually using append logic for the additional modules that can be
included by a prepend.

Before all the modules from the prepended module were prepending,
resulting in a wrong ordering.

The redefinition problem is solved by making origin just a marked for
redefinition if it's different. This results in lookup logic to skip
that class / module that has a different origin and encounter it later
because it was readded as an included module later.
Remove tags for now passing specs