add slugs to routes

this commit replaces the previous behaviour of linking to lemma ids.
Instead all lemmas can now be accessed both ways, via slug and id,
however, ids forward to slugs giving them a first class citizenship.

Hopefully this will improve seo a bit.
fix bs3 rename bug
update copyright
fix missed slug updates and make sure unchanged lemmas wont change the slug
normalize routes

make /:slug a first class citizen and all other routes secondary.
This will make dictionary entries a lot more appealing in search
engines. Adapted specs as well as routes for this.
if a :slug lookup fails redirect to search

this method doesn't work perfect as umlauts are dropped during
slugging so finding them is a problem and searching for a slugged
entry is also silly.

Try farhang.im/Wörterbuch and you won't find it because it is
under farhang/im/woerterbuch. However, if you try farhang.im/woerterb
it will not find Wörterbuch because oe != ö. Anyway, edge cases.
version bump to 1.1.0
fix broken sitemap table