Worked on vocabulary

[Benjamin Mesing]

Hello,

> Benjamin: if you want to try with the new vocabulary, you should be able
> to do it by checking it out of the website, copying it on
> /var/lib/debtags/vocabulary and running debtags update.
Its nice - everything works fine as the base structure of the file
stayed stable :-). Nevertheless, I think I should not allow people to
select items flagged as "empty".
My application has detected an inconsistency in the vocabulary file:
library::algorithm implies library which is not in the vocabulary
database. It seems this was forgotten.

> Phew!  What a work...  The vocabulary's becoming quite big!
Great work - I think the result was worth the effort!

Greetings Ben