use consistent file and directory names

[paulcobbaut]

The modules directory should contain exactly one directory for every chapter (and one chapter for every directory). The filenames in each directory should have a consistent naming scheme. For example :
mod_working_with_directories
mod_working_with_directories/directories_theory.xml
mod_working_with_directories/directories_practice.xml
mod_working_with_directories/directories_solution.xml
mod_working_with_file_contents
mod_working_with_file_contents/filecontents_theory.xml
mod_working_with_file_contents/filecontents_practice.xml
mod_working_with_file_contents/filecontents_solution.xml
mod_working_with_files
mod_working_with_files/files_theory.xml
mod_working_with_files/files_practice.xml
mod_working_with_files/files_solution.xml

This allows (in the future) for easy separation of an 'exercise' book and a 'solutions' book for the students.
This potentially obsoletes (the maintenance of) the books/chapters file.

Paul is currently working on this and will commit when (the fundamentals part is) ready.

[paulcobbaut]

1. Committed a bit too soon, working in "experimental" branch from now on!
2. four chapters "introduction", " getting help", "shell history" and "access control lists" do not have practices (yet)
3. Shortening the chapters (modules) to little chapters with one part theory and one part practice makes one notice that certain parts need to be improved (or rewritten).

[paulcobbaut]

ah, was this finished? ;-)
The minibooks are all there, as are the directories and the books. It all builds (on my system), but with problems (some stuff still in Dutch, some modules still need to be split, the toc is often messed up).
But some directories contain too many files!! Which are now just added in alphabetical order. I still want to migrate all this to proper filenames!