A bunch of smaller test improvements.

 * Use builtin all function for clarity.
 * Rename retval -> result for consistency.
 * Replace len(x) > 0 with len(x) in asserts.
 * Fix change in 7009094 that broke a test.
 * Add variables un_pswd, other_user_pswd other_non_mod_name and
     other_non_mod_pswd. Use them where their value was given
     explicitly before.
 * Remove sort param in get_new test. With the splitting of the new
     listing into a new and rising listing this is no loner neccesary.
 * In get_mod_queue_multi use self.priv_sr over "reddit_api_test2" as
     this subreddit is also used elsewhere in the testing.
 * In test_scope_modlog give limit explicitly rather than relying on
     default. Otherwise a change in default or self.un preference will
     cause the test to fail. Set limit=50 for consistency.
Add UnauthenticatedReddit.get_rising