Change from SplFileInto to Symfony Finder

[renatomefi]

Doing this change will allow the user to make complex file search like:

<permcheck>
    <excludes>
        <dir>vendor/</dir>
        <dir>.git/</dir>
    </excludes>
    <executables>
        <dir>bin/*</dir>
        <dir>bin/*/tests/*</dir>
    </executables>
</permcheck>

[eXistenZNL]

This was also a request from @blangerak, and although I didn't think of Symfony Finder, I concider using it as dependency instead of coding it myself. Will add this in the near future for sure :)

[QassaDevelopers]

+1. It would be very helpful (for us) if this tool would support glob patterns for both the excludes and executables.

Is there any chance this will be implemented soon?