Add array_has function
Fix a bug which caused irregular plural words to have an S appended when passed to Pluralizer::plural
Bugfix for long random strings and more randomness
Remove % from filenameFallback in Response::download

Because it's not allowed in the fallback name.
(See https://github.com/symfony/symfony/blob/v2.5.5/src/Symfony/Component/HttpFoundation/ResponseHeaderBag.php#L264-L277)
Updated to be able to access all bags.

For ability to have a generic error handler for all bags in case they are grouped like `register[email]`. It's not possible to know what the grouping is unless `$errors->register->getMessages()` is specifically called.
Corrected Function Comment
Allows array_only to handle dotted keys
useless previous instanciation of $dotted variable
Ensure we can fetch an array with non existing keys
Merge pull request #5746 from lucasmichot/4.2-array-only-dotted

[4.2] Allows Arr::only To Handle Dotted Keys
Merge pull request #5765 from lucasmichot/4.2-support-helpers-array-has

[4.2] Added Arr::has
Fix casing.
Merge pull request #6075 from egeriis/4.2

[4.2] Fixed A Pluralization Bug
Merge pull request #6097 from barryvdh/patch-4

[4.2] Remove % From filenameFallback In Response::download
Merge pull request #6085 from khayyam90/4.2

[5.0] More Randomness In QuickRandom
Merge pull request #6151 from websanova/4.2

[4.2] Updated To Be Able To Access All Bags