Part 1: Miscellaneous minor standards cleanups.
Part 1: 2301239 Cleaned up class in StaticMenuLinkOverridesInterface.php
Part 1: cleanup on MenuTreeStorage.
Part 1: clean up. defaults was not actually inherited. looked at local tasks for confirmation. mentioned where it needs to stay in sync with.
doxygen fixes
small doc fixes to examplin NULL route
Part 1: Few more 'add s' fixes.
Part 1: typo fix in MenuTreeStorage.
Part 1: forgot to take out condition that used the parameter that was removed: prevent reparenting
Part 1: docs rewrapping in MenuTreeStorageInterface.
rename create/delete to add/remove
START PART 2:  https://www.drupal.org/node/2301273
apply patch https://www.drupal.org/files/issues/menu-2256521-MenuLinkTree-review-do-not-test.patch