vcs: Minor changes to exercises.rst
Changed the directory structure of exercises repository and
accordingly changed the exercises sheet.
Richard Stallman%http://www.stallman.org
Eric Raymond%http://www.catb.org/~esr/
Ian Murdock%http://ianmurdock.com/
Lawrence Lessig%http://lessig.org
Linus Torvalds%http://torvalds-family.blogspot.com/
Guido van Rossum%http://www.python.org/~guido/
Larry Wall%http://www.wall.org/~larry/