translate x_hours in many languages (#14221)

Contributed by Filou Centrinov.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11932 e93f8b46-1217-0410-a6f0-8f06a7374b81
remove trailing white-spaces from lib/redmine/plugin.rb

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11933 e93f8b46-1217-0410-a6f0-8f06a7374b81
Japanese translation updated by Go MAEDA (#14224)

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11934 e93f8b46-1217-0410-a6f0-8f06a7374b81