WebStyle: new handle_file_post API
WebStyle: new handle_file_post API

* New API handle_file_post to handle direct POSTing of files.

* New web testing infrastructere for HTTP (and WSGI and SSO) under /httptest/.

* Cleaned unneeded definitions from webinterface_handler_wsgi_utils.py
  and moved constants and Exceptions into webinterface_handler_config.py.

* Improved handling of posted file in websubmit_managedocfiles.py.

inspirehep/invenio-accounts,inveniosoftware/invenio-accounts,inveniosoftware/invenio-accounts,inspirehep/invenio-accounts,tiborsimko/invenio-accounts,inveniosoftware/invenio-accounts,tiborsimko/invenio-accounts,inspirehep/invenio-accounts,tiborsimko/invenio-accounts