doc: use "Groonga" notation in normalizers.txt and its .po
Merge pull request #140 from cosmo0920/use-Groonga-notation-reference

doc: use "Groonga" notation api/* and reference/*

Patch by cosmo. Thanks!!!
Merge pull request #141 from cosmo0920/use-Groonga-notation-normalizers

doc: use "Groonga" notation in normalizers.txt and its .po

Patch by cosmo. Thanks!!!
doc types.txt: use "Groonga" notation