Chapter 4

Updates the table "Content elements" and solves the problem with the
links in the tables.
Updates tables of modules.
Some HTML tags can not be converted (Insert tags in tables).
Adds <abbr> tags.
Added the <code> tag instead of single quotes
 Chapter 4 (in German)

Updates the table "Content elements" and solves the problem with the
links in the tables.
Updates tables of modules.
Some HTML tags can not be converted (Insert tags in tables).
Adds <abbr> tags.
Adds the <code> tag instead of single quotes
Remove "abbr" tags
Merge remote-tracking branch 'lionel-m/chapter-4' into 3.0
Translated "Click here" in the german manual
Added minor corrections to lionel-m's pull request