Compatibility with Princeton wordnet

It would be handy if the database was provided in the same format as other wordnet databases. If this were the case, already existing interfaces, such as the wordnet-cli/wn interfaces provided by the Princeton WordNet project, could be use together with this Dutch database. This will be really beneficial for the scripting community at large; e.g. to my knowledge, there is no good offline dutch traditional dictionary database (except maybe this one) but it's quite hard to properly integrate the Dutch database as it exists now into existing dictionary lookup programs. Same for other purposes you might think of. As it stands now, the current database---at a glance at least---seems kinda scattered and to be made out of different kind of files in different formats.

For example, the Princeton wordnet program contains a directory structure like this (and theoretically already allows you to use different "dictionaries"):

...
/usr/share/wordnet/dict/adj.exc
/usr/share/wordnet/dict/adv.exc
/usr/share/wordnet/dict/cntlist
/usr/share/wordnet/dict/data.adj
/usr/share/wordnet/dict/data.adv
/usr/share/wordnet/dict/data.noun
/usr/share/wordnet/dict/data.verb
/usr/share/wordnet/dict/noun.exc
...

Start by inventorying the current database files and comparing them with the Princeton WordNet dict directory and file layout shown in the issue. The work is done when the Dutch data can be used with the existing wordnet-cli/wn interfaces without requiring a separate scattered-file integration.