Japanese translation updated by Go MAEDA (#17166)

git-svn-id: http://svn.redmine.org/redmine@13180 e93f8b46-1217-0410-a6f0-8f06a7374b81
Gemfile: pin request_store version 1.0.5 (#16685)

Many integration tests are broken.

git-svn-id: http://svn.redmine.org/redmine@13181 e93f8b46-1217-0410-a6f0-8f06a7374b81
Merged r13180 from trunk to 2.5-stable (#17166)

Japanese translation updated by Go MAEDA.

git-svn-id: http://svn.redmine.org/redmine@13182 e93f8b46-1217-0410-a6f0-8f06a7374b81