Simplify JobQueySet (#1344)
Simplify JobQueySet (#1344)

* Remove redundant exact lookups. 'exact' is the default
  lookup type.
* Remove unnecessary Q objects. Filters are 'and' by default.
* Simplify active lookup by reusing the approved method.
* Use exclude() instead of negated Q.

python/pythondotorg,python/pythondotorg,python/pythondotorg,python/pythondotorg,proevo/pythondotorg,manhhomienbienthuy/pythondotorg,manhhomienbienthuy/pythondotorg,manhhomienbienthuy/pythondotorg,proevo/pythondotorg,manhhomienbienthuy/pythondotorg,proevo/pythondotorg,proevo/pythondotorg