Initial work to create dokuwiki write (#386)

In this first version, all dokuwiki files are straight copies of the
media wiki counterparts.
Added default.haddock.
Merge remote-tracking branch 'jgm/master' into dokuwiki
Merge pull request #65 from claremacrae/dokuwiki

Merge in template file for Dokuwiki support
Added `type="text/css"` to link tags in epub3 template.
Merge remote-tracking branch 'upstream/master'