Fixes #17343 - set deep munge config off

deep_munge was introduced as a solution to keep
Rails secure by default which results in
'empty array becomes nil in params'.
Thats why, set deep_munge config off in application.rb.
Also, added changes which will cast param argument to string...

Refs #3809 - Turning on the AndOr cop

Refs #3809 - Turning on some rubocop cops

Fixes #13230 - Oauth headers change in rails 4

Refs #3809 - Remove cops for empty lines

Fixes #7233 - Drop Ruby 1.8.7 and revert Ruby 1.8.7 specifics

Refs #3809 - Remove rubocop TODOs

Removed the following TODOs so that cops for these will run from now on:

Lint/AmbiguousOperator, DefEndAlignment, DeprecatedClassMethods
EnsureReturn, RequireParentheses, Void, BlockAlignment, EndAlignment,
UselessAccessModifier,...

Fixes #7738 - logout_url is nil by default for all SSO backends

fixes #7737 - no specific logout URL needed, will go directly back to login.

Fixes #3840 - Removes unused Signo related code