Support Rails 4 (work well with test-unit-activesupport 1.0.2)

I checked this gem works well by simple Rails tests
(model/controller/integration), through it may not cover all tests for
Rails, but I can't check it now... so when I find the bugs of this gem,
I will fix.
doc: add 1.0.3 entry
doc: use tset-unit.github.io as website of test-unit-rails
doc: update supported version
doc: add my name to author
doc: add missing settings for locale to Packnga configurations
doc: update po
doc: translate