Ensure that we sanitize any `AC::Parameters` in `find_or_initialize_with_errors`.

 As we are already slicing the Hash, we must be sure that this method will send
 a "safe" object down to the other finder methods that will use the Hash entries
 to do the querying.
Silence controller generator warning output
Merge pull request #3162 from plataformatec/lm-sanitizer-to-hash

Do not pass down 'ActionController::Parameters' to outside the controller
Update README.md

Added the security shield from Hakiri.
Merge pull request #3216 from vasinov/master

Update README.md
use authentication_keys in flash message, instead of static ‘username’ (fix #3201)
Merge pull request #3218 from timoschilling/fix_3201

use authentication_keys in flash message (fix #3201)
fix argument bug

when `is_navigational_format?` returns false, Exception will be throw: 
ArgumentError (Nil location provided. Can't build URI.)
Merge pull request #3229 from yandy/patch-1

fix path bug
Merge branch 'master' into lm-rails-4-2
Update Rails dependency
Remove ActiveSupport test order deprecation warning