Fix line-collision on wrapped header titles
batch actions allow add a proc to form parameter.
Fix i18n for pluralized model names

On Rails 4.0, translating a model with count: 1.1 was returning the
singular version.
Just a small addition, so now we can remuve multiple filters inline
added unit test
Add better loking template for registrations#new view for admin users. Locale for English and Polish is added.
Merge pull request #2852 from avelexvi/2835-exclude-specific-filters

Just a small addition, so now we can remove multiple filters inline
Merge pull request #2855 from krzysztofbialek/#2790

Properly styled registrations#new template for admin users
Revert "make CSV downloads respect pagination"

This reverts commit a8ad4f989caec3a9ffbc820a949f309d2ce1a832.

Ref: #2847
Merge pull request #2627 from shekibobo/fix-multiline-header

Fix line-collision on wrapped header titles
Merge pull request #2778 from WilliamZang/master

batch actions allow add a proc to form parameter.
updates to #2778
add 'equals' to the filter predicates that default to string

as discovered by @JakeAustwick in IRC:

https://botbot.me/freenode/activeadmin/msg/9660435/
refactor tests for string filters w/ a predicate (e.g. body_equals)
lock Travis icon in README to the master branch
Add ability to order by hstore columns in PostgreSQL

Example:

```ruby
class Device < ActiveRecord::Base
  store_accessor :information, :model
end
```

```ruby
ActiveAdmin.register Device do
  index do
    column :model, sortable: "information->'model'"
  end
end
```
Merge pull request #2844 from AndreyChernyh/f/add-hstore-sort

Add ability to order by hstore columns in PostgreSQL
#2414: don't accidentally set up AA routes multiple times
Support scopes with spaces in the name
clarify the state of the project in the README