Update to 5.48

Upstream changes:
5.48  2014-10-07
  - Emergency release for a serious security issue that can result in
    parameter injection attacks, everybody should update!
    Breaking change: Methods that previously worked differently in scalar than
    in list context now always assume scalar context, and new methods have
    been added to cover the list context functionality.
  - Added every_cookie and every_upload methods to Mojo::Message.
  - Added every_param method to Mojo::Message::Request.
  - Added every_param method to Mojo::Parameters.
  - Added every_cookie, every_param and every_signed_cookie methods to
    Mojolicious::Controller.
  - Added every_param method to Mojolicious::Validator::Validation.
  - Added from_json and to_json functions to Mojo::JSON.
  - Improved pluck method in Mojo::Collection to be able to extract values
    from hash references.

(wen)