Make FIELD_ERROR_PROC configurable

Minor change on field_error_proc

Make FIELD_ERROR_PROC configurable, activerecord helper to active model helper
Setting custom field_error_proc test
Do not expect a controller to exist when looking up action
add test for controllerless form
update CHANGELOG
bump rails version to 4.0.0.rc1
Add nodoc to internal lookup methods

These methods are completely internal for the inputs to use and should
never be called from outside.

I just hope no one ever creates an attribute called "lookup_action" :D.
Ensure that field error proc is swapped by simple_form_for
Depend on r.0 rc1
Do not subclass Struct.new when unnecessary
Remove dead stuff from test models
Require bundler gem tasks instead of installing them manually

[ci skip]
No need to require rubygems anymore
Remove unnecessary test
Remove field_error_proc doc from initializer
Merge pull request #773 from dfens/master

Make FIELD_ERROR_PROC configurable
update CHANGELOG [ci skip]
Merge pull request #759 from tubaxenor/patch-1

Relation#all is deprecated in Rails 4, use Relation#to_a instead

Conflicts:
	test/support/models.rb
Remove not used methods
Refactor test models to always delegate to a fake Relation object

This way both where and order methods are part of the fake relation
object and everything is delegated to that. Also, if we end up changing
the implementation to call some other method the we want this to fail
miserably, and it's better to use a bare object rather than an array to
avoid it passing by mistake.