set version number to 3.2.1
use proper numbers for OR queries and handle NULL in FindSqlGenerator (fixes #373)
fix #373

- the filled NULL columns need the name "salt_idX" instead of "node_nameX"
- when not using the AbstractUnionSqlGenerator we have to make sure the selected alternative has the same size as QueryData#getMaxWidth()
sort the root nodes by their left_token value before adding their subgraphs to the list

this fixes #371 and makes sure the graphs are outputted in the correct order
harmonize the creation of the meta data tables in the document browser and the corpus browser (fixes #370)
don't call "onLogin" notifier when login attempt was not successful

this fixes #374
create a random salt on hash generation (fixes #375)
updating CHANGELOG
Finish annis-3.2.1