Remove comparison of class names

This was added by a [patch a couple of years
ago](https://github.com/ryanb/cancan/commit/79180de3722673388c1eb65fc09db5a72fe0b1a8),
apparently to fix a problem with class reloading. I'm not sure if that problem
still obtains but the string comparison is a performance bottleneck, and
removing it should not change the semantics of the method.
\#resource_class can accept a proc.
removed rr, bump rspec version to 2.14, expect syntax, ruby 1.9.3/2.0.0 compatible
ruby 1.8 style hash syntax
use expect syntax for Mongoid and DataMappper specs
removed should spec wording, same as on the 2nd branch
Added lookup for :attributes key in arguments passed to load_and_authorize_resource looking for a params sanitation method name.  The params sanitation method defined in the client apps controller is then used to get the params when loading the resource.
Fallback to legacy behavior if no attributes method specified.  Added spec for new attributes method functionality.
treat ActiveRecord::Relation as Array
Reduce object allocations
Update active_record_adapter.rb

As @dim suggested in #889
Please refer to that issue for more information. Note that I did't came up with this idea, @dim did :smile:
Merge branch 'ForbiddenAttributes' of github.com:blischalk/cancan

Fix ActiveModel::ForbiddenAttributesError on Rails 4
Merge branch 'master' of github.com:neubloc/cancan

Fixes the problem with Rails 4, where ActiveRecord::Relation is no longer recognized as Array, which gives problems when defining abilities with joins - see #916
Merge branch 'eac/optimize' of github.com:eac/cancan

Micro-optimization to reduce object allocations
Merge branch 'patch-1' of github.com:davidakachaos/cancan

Mitigate possible variable overwrite in CanCan::ModelAdapters::ActiveRecordAdapter#tableized_conditions
Merge branch 'modern-rspec' of github.com:ogerman/cancan

Remove RR, Update RSpec to 2.14, new expect syntax
Merge branch 'master' of github.com:jamesmoriarty/cancan

Allow ControllerResource#resource_class to utilize Proc's
Merge branch 'remove_string_comparison' of github.com:RapGenius/cancan

Performance optimization: Remove class name string comparison
Merged a modified version of ncrl's strong parameter PR, see ryanb/cancan #868