Refactor CLI code.

* Hash keys to symbols
* Avoided using OVERRIDES[kind] over and over using a variable.
Refactor: Removed many unneeded parentheses.
Refactored DashboardHelper#activity_message_for to remove complexity.
Fixed the expectation for override failure message as it has changed.
Update changelog.
Added missing Polish translations for pages.
added missing i18n PL translations for wymeditor
Tidy up invalid YML.
Move wysiwyg fields into a partial for easier maintainability.
Update changelog.
Added mocking to controller specs.

Also converted requests/controller_restriction_spec.rb to controllers/dummy_controller_spec.rb
Allow transactional database strategy with Selenium.
Add spec to ensure proper attributes gets added to attr_accessible list.
Merge remote-tracking branch 'origin/issue_1657'
Removed created_at and updated_at from mass assignment.
Bump rspec-rails version and drop rack-test from testing dependencies because we aren't tied to it directly.
Use absolute require for version in gemspec
Check to ensure render_with_templates? is defined when executing 404 page

Fixes #1795. When the error_404 method is called outside of the scope of the
PagesController, as it can be, since extensions also are extended, too, the
render_with_templates? call will throw a NoMethodError.
This might also be rewritten as a redirect to the 404 page,
which I think might be a better choice in the long run, but needs to be discussed.
Merge remote-tracking branch 'origin/fix-error-404'

Conflicts:
	testing/refinerycms-testing.gemspec
Fixes .../edit&switch_locale=en... bug with copywriting.