make sure static subdir 404s correctly

before each request, we put the current service on the flask session,
except for with the static folder, cos it's not needed.... except, if
we 404, then we return the 404 template, which checks if you're logged
in or not to display different nav bar items. This was crashing when
current_service wasn't set, so we now set it.

also cleaned up some imports and stuff in test files

app/__init__.py

@@ -21,7 +21,7 @@ from flask import (
     g,
     url_for)
 from flask._compat import string_types
-from flask.globals import _lookup_req_object
+from flask.globals import _lookup_req_object, _request_ctx_stack
 from flask_login import LoginManager
 from flask_wtf import CsrfProtect
 from functools import partial
@@ -380,10 +380,10 @@ def load_user(user_id):
 
 def load_service_before_request():
     if '/static/' in request.url:
+        _request_ctx_stack.top.service = None
         return
     service_id = request.view_args.get('service_id', session.get('service_id')) if request.view_args \
         else session.get('service_id')
-    from flask.globals import _request_ctx_stack
     if _request_ctx_stack.top is not None:
         _request_ctx_stack.top.service = service_api_client.get_service(service_id)['data'] if service_id else None