As durable history enables cursor caching for the history store, some errors were reported in test_cursor13.py.  Most errors have been resolved (by fixing the test).  There are two remaining errors, the associated tests have been marked to be skipped.  We should investigate why they fail and fix the tests.  It seems likely the problems are in the test, rather than in the WT implementation.

See https://github.com/wiredtiger/wiredtiger/pull/5239/files for the commit that added the unittest.skip notations.