Add xtas module, set amcat to use celery
Merge branch 'master' into xtas
adjusted celery settings
test bug
add cache_clear, force_resend options
added corenlp to amcat source tree and stub naf class
naf output from stanford
add to_dict
bugfix
remove log
to/from json, bugfixes
testlines should be classmethod
Merge branch 'nestedrest' into xtas
xtas resource and bugfixes
return results for stanford
move semafor to amcat.nlp
link semafor to naf
add xtas navigator view
add frames to naf
convert syntaxtree to naf