Checks that there are no tab characters ('\t') in the source code. Rationale:
- Developers should not need to configure the tab width of their text editors in order to be able to read source code.
- From the Apache jakarta coding standards: In a distributed development environment, when the commit messages get sent to a mailing list, they are almost impossible to read if you use tabs.
This rule is deprecated, use {rule:squid:S00105} instead.