objects of type=file are now visible in GUI
- The file.jsont does not contain filename information, so often files
will be displayed using the couchdb ID. Except in analysis overview,
where filename can be found using the parent setting and the url
documents (this only works if there's a url reporter in the workflow)
- also add the added couchdb views 'file_by_fwid' and 'file_summary'.

commit is related to issue #5
Merge branch 'master' of https://github.com/CERT-Polska/hsn2-webgui.git