Feature/rails3

## Feature

* Update for rails 3.1.  #paged_scope() was using AssociationCollection#scoped() to set limit and offset, but args are no longer supported on #scoped().  Update to use AREL limit and offset instead.
* Many updates to fix broken test suite.  Update frozen rails app in rails_root used by test suite, Gemfile, and related code so test suite can run.
* Updates for echoe/gemspec/Manifest generation.

Will tag as v1.0.7 after merge.

## Testing

Test suite runs and passes!

[cherbst:pagem]$ bundle exec rspec spec/pagem_spec.rb 
~
......................

Finished in 0.05956 seconds
22 examples, 0 failures

Core Balance scenarios passing too:

[cherbst:work]$ be cucumber features/general/page.feature 
~
10 scenarios (10 passed)
88 steps (88 passed)
0m9.847s