Fixed invalid h0 header tags

Changed the way bookmark tags are created to a more robust method.

The algorithm is no longer dependent on level 1 heading (the previous
one caused problems if the first heading was not a level 2 heading).
translation update
Merge pull request #94 from mechkg/master

Fixed invalid h0 header tags
Merge pull request #118 from dokuwiki-translate/lang_update_64

Translation update (no)