* Add support for `mysqldump`'s `--ignore_table` switch.
* Fix documentation and default linter warning re: default parameter
* Add number to replacement field in cmd string
* Bump version_added to 2.7
This change corrects problems reported by the `yamllint` linter.
Since key duplication problems were removed in 4d48711, this commit
mainly fixes trailing spaces and extra empty lines at beginning/end of
files.