introduce request_store to ensure that the current user doesn't leak across request boundaries (#16685)

Contributed by Holger Just.

git-svn-id: http://svn.redmine.org/redmine/trunk@13110 e93f8b46-1217-0410-a6f0-8f06a7374b81
Gemfile: use double quote for request_store (#16685)

git-svn-id: http://svn.redmine.org/redmine/trunk@13112 e93f8b46-1217-0410-a6f0-8f06a7374b81
add patch for regression of Hash#reject in Ruby 2.1.1 (#16194)

git-svn-id: http://svn.redmine.org/redmine/trunk@13115 e93f8b46-1217-0410-a6f0-8f06a7374b81