Supports voting on embedded objects for Mongoid

Does not support MongoMapper, and still needs a bunch of cleanup and
tuning.

The goal here was to support one level deep embedded objects. It relies
on _root being defined on the object, and some other standard patterns.

Would appreciate feedback.

Squashed commit of the following:

commit 619c2a70441da8edaffb8cef6d9e12abc58ec989
Author: sujal shah <codesujal@gmail.com>
Date:   Tue Oct 18 17:12:11 2011 -0400

    All tests pass!

commit b644e0ba8d31572ac8894ac7ee904f20c87f64f8
Author: sujal shah <codesujal@gmail.com>
Date:   Tue Oct 18 00:01:32 2011 -0400

    First pass at embedded object voting support

commit e04717967146db8f043c12846a87636faa926ef2
Author: sujal shah <codesujal@gmail.com>
Date:   Mon Oct 17 12:47:30 2011 -0400

    checking in interim work

    i want to keep this in case it's necessary, but I don't think it is.

commit 683b4d2c4d7e4a550b232b82433ce5f81471c316
Author: sujal shah <codesujal@gmail.com>
Date:   Fri Oct 14 22:06:59 2011 -0400

    checking in interim work

commit 6c4caf94c8658bf96632042f0561f4c569f8667e
Author: sujal shah <codesujal@gmail.com>
Date:   Fri Oct 14 22:06:48 2011 -0400

    query that needs to be run - notes, will be deleted

commit e81c9c134d151e206f61b1203cf16d533a7c5903
Author: sujal shah <codesujal@gmail.com>
Date:   Fri Oct 14 22:06:13 2011 -0400

    this is the test to validate

commit 5d80303ed4bfe04478a05d7351ee25a817d3a8f0
Author: sujal shah <codesujal@gmail.com>
Date:   Fri Oct 14 22:05:44 2011 -0400

    this is a proposed solution
cleanup

this shouldn't have been committed
oops, forgot to undo this testing hack
bug affecting mongomapper users

I forgot to check if the model had an embedded? method in one place.
Get rid of deprecation warning for the InstanceMethods module inside ActiveSupport::Concern
Merge branch 'master' of git://github.com/towynlin/voteable_mongo

Conflicts:
	lib/voteable_mongo/voteable.rb
	lib/voteable_mongo/voter.rb
merge in embeddable changes