Separate Kaminari theme

Prevents ActiveAdmin's pagination from being overriden by any
customizations made to the Kaminari views in a Rails app that uses
ActiveAdmin. Fixes gregbell/active_admin#1126.
Added permit_params dsl
Pass permit_params block to params.permit
Added newlines
Improve comments_spec styles and readability
Make resource_type of AA::Comment respect STI
Convert tabs to spaces
reorganize javascript folder structure
Fix overlapping flash message on non-logged pages

Add some margin-bottom to flash messages on logged out pages
Merge pull request #2651 from brennovich/2650-overlapping-flash-messages-on-login

Fix overlapping flash message on non-logged pages
has_many javascript refactor

First and foremost, this commit moves the JS `onclick` calls out into
their own dedicated file. This also adds before & after hooks so you
can more easily update dynamic parts of the form, for example if you're
using a plugin like Chosen for interactive dropdowns:

```coffee
$ ->
  $(document).on 'has_many_add:after', '.has_many', (e, fieldset)->
    fieldset.find('select').chosen()
```

There's one other change here: I switched around the text used for
has_many deletion because it didn't make sense to me that delete was
applied to something that hadn't yet been saved, while remove was used
for already-saved records.
Merge pull request #2645 from seanlinsley/refactor/has_many-form

Refactor the has_many form
Allow datepicker options to be passed to datepicker_input

Allows :max_date and :min_date options (or other jQueryUI datepicker
options) to be passed to :datepicker input.

```ruby
f.input :starts_at, as: :datepicker, datepicker_options: {min_date:
"2013-10-8", max_date: 3.days.from_now.to_date}
f.input :ends_at, as: :datepicker, datepicker_options: {min_date:
3.days.ago.to_date, max_date: "+1W +5D"}
```
bugfix for #2645

'doh
Merge pull request #2578 from shekibobo/datepicker-advanced

Allow min/max dates to be set on datepicker input
Add documentation about datepicker input options

[skip ci]
#2646: update example in the initializer
#2646: provide absolute path example for site_title_image
GFM docs update
update 8-custom-actions.md