Merge branch 'ab/test-lib-updates'

Merge branch 'ab/test-lib-updates'

Test clean-up.

* ab/test-lib-updates:
  test-lib: split up and deprecate test_create_repo()
  test-lib: do not show advice about init.defaultBranch under --verbose
  test-lib: reformat argument list in test_create_repo()
  submodule tests: use symbolic-ref --short to discover branch name
  test-lib functions: add --printf option to test_commit
  describe tests: convert setup to use test_commit
  test-lib functions: add an --annotated option to "test_commit"
  test-lib-functions: document test_commit --no-tag
  test-lib-functions: reword "test_commit --append" docs
  test-lib tests: remove dead GIT_TEST_FRAMEWORK_SELFTEST variable
  test-lib: bring $remove_trash out of retirement