strip: properly clear resolve state with --keep (issue4593) Normal updates automatically clean up the resolve state, but strip --keep does a "manual" update that bypasses the normal machinery. This adds a mergestate reset.

revsets: more informative syntax error message I came across a case where an internal command was using a revset that I didn't immediately pass in and it was difficult to debug what was going wrong with the revset. This prints out the revset and informs the user that the error is with a rebset so it should be more obvious what and where the error is.

revsets: show current revset abort behavior

tests: move blackbox testing of tags to test-tags.t We're going to refactor tags cache shortly. It is easier to test the blackbox logging if these tests are in test-tags.t.

tests: move mock blackbox extension into own file Having all blackbox log testing in test-blackbox.t isn't scalable. Move the mock blackbox extension into its own file so we can start to move blackbox logging into other tests.

shelve: acquire lock in the right order Text book says that 'wlock' should be acquired before 'lock'. Caught through developer warning.