Merge branch 'dl/format-patch-doc-test-cleanup'

The documentation and tests for "git format-patch" have been cleaned up. * dl/format-patch-doc-test-cleanup: config/format.txt: specify default value of format.coverLetter Doc: add more detail for git-format-patch t4014: stop losing return codes of git commands t4014: remove confusing pipe in check_threading() t4014: use test_line_count() where possible t4014: let sed open its own files t4014: drop redirections to /dev/null t4014: use indentable here-docs t4014: remove spaces after redirect operators t4014: use sq for test case names t4014: move closing sq onto its own line t4014: s/expected/expect/ t4014: drop unnecessary blank lines from test cases