Add support for PHP.

This supports allowing you to create a ruleset for your php projects.

This does not support everything:
1) Custom violations.
2) Include/exclude directories.
Useless assignment to variable - `wait_thr`. Use `_` or `_wait_thr` as a variable name to indicate that it won't be used.<br>Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.