fixed some general problem about using LaTeX syms
Use Stallman when it should be.
Use Stallmen when it should be in Chapter 04.
Richard->Stallman chap05
Richart->Stallman 06
Richard->Stallman chap07
Richard->Stallman
Minor change in chapter 9
Merge pull request #1 from monnand/v1

Change Richard to Stallman when necessary