Add french book "Introduction à Scilab", Baudin, Glebov, Briot
Add german book "Einführung in Scilab/Xcos 5.4", Büch
Add book "Introduction to Scilab", M. Baudin
Add russian book "Введение в Scilab", M. Baudin
Add "Writing Scilab Extensions", M. Baudin
Add "Programming in Scilab", M. Baudin
Add russian book "Программирование в Scilab", M. Baudin
Fix typo
Merge pull request #269 from ericguirbal/scilab

Add books on Scilab