Add new translations (but not activated yet):

Makefile
book.sgml
chapter.decl
chapters.ent
overview/chapter.sgml
psgml-mode/chapter.sgml
see-also/chapter.sgml
structure/chapter.sgml
stylesheets/chapter.sgml
tools/chapter.sgml
writing-style/chapter.sgml

Submitted by: Kenji Sato <ken@ny.kdd.com>, hrs