correct release_type/release_status checking

For both we can filter if we have the right includes OR
the right entities (important for browsing).
Release groups only have a status, but releases have a type and status,
since that is inherited by the group.

I also made PEP 8 changes to the checking function.

Signed-off-by: Johannes Dewender <github@JonnyJD.net>
Merge branch 'status_type' into doc_changes

We want to tell people to filter while browsing whenever possible,
so the filter possibilites should be available.

Signed-off-by: Johannes Dewender <github@JonnyJD.net>
document browsing usage

This example explains paging and tries to persuade the user to filter
the query whenever possible.

The example will only fetch 2 pages (168 releases).
That is bigger than the highest limit, so paging is necessary,
but won't strain the server too much when the examples are tried.

This needs the fix to filter by releases by type.
(merged in this branch)

Signed-off-by: Johannes Dewender <github@JonnyJD.net>
describe release_types and release_statuses

They can only be used in certain circumstances.

Signed-off-by: Johannes Dewender <github@JonnyJD.net>