remove old comments
remove deprecated ButtonsHelper, buttons DSL and commit_button helper
make this a bit more generic
deprecated the top-level :value option that is only used by HiddenInput
deprecated :hint_class and :error_class options (use global configs)
remove warnings from old options
notes
deprecated :group_by and :group_label options
deprecated :find_options option
Merge pull request #820 from twalpole/rails4

Allow use with Rails 4 edge
Revert "Merge pull request #820 from twalpole/rails4"

This reverts commit e4f3b049858e5f4f7adfc7e2ff3d9e141ff5cecb, reversing
changes made to 0f42a5ce74f4f980ad35353079c1de96bfee853b.

Work still exists in rails4 branch until ready to re-merge.
Update build matrix to not test ruby 1.8.7 and ree with rails 4 (edge)
Make travis exclusion work
rails edge requires 1.9.3 so exclude testing with 1.9.2
ignore .ruby-version
Merge branch 'master' into rails4

* master:
  ignore .ruby-version
  Revert "Merge pull request #820 from twalpole/rails4"
Revert "Revert "Merge pull request #820 from twalpole/rails4""

This reverts commit 363d51e8910ecf8640add799586166f40c0894cd.
Use sprockets-rails from github until its on gemcutter
skip Rails 4 tests locally unless RAILS_4=true, let CI catch them for now
looks like we don't need sprockets now?