Merge pull request #134 from cosmo0920/use-Groonga-notation-tutorial-ja

doc: use "Groonga" notation ja/tutorial

Patch by cosmo. Thanks!!!
doc contribution.txt: use "Groonga" notation .txt and .po
doc com.txt: use "Groonga" notation
doc cooperation.txt: use "Groonga" notation
doc document.txt: use "Groonga" notation
doc query.txt: use "Groonga" notation
doc repository.txt: use "Groonga" notation .txt and .po
doc test.txt: use "Groonga" notation
doc release.txt: use "Groonga" notation
doc: remove trailing spaces