Add --ignore-paths and --extensions options

[hanneskod]

Add the possibility to ignore paths and specify file extensions to parse. Basically enhances the behaviour of FileIterator.

[redbeardcreator]

I'm not sure why you're using array_filter() here. Are you expecting it to remove empty values? If so, that's fine, but it's a little obscure. I didn't realize it was usable like that until I just looked it up. I'd be tempted to refactor that bit (array_filter(explode(...))) into a separate method and document this use of array_filter(). But also see my other comments.

[redbeardcreator]

This looks great! I haven't tested yet, but a visual inspection looks good.

I did have a minor question, but I think I answered it. Just in case I misread the second time, here it is.

Why does --ignore-paths take a comma separated list but the path used InputArgument::IS_ARRAY? I believe it's because I misread it thinking that it was a --path option, not an argument. I was just wondering if they should be more consistent. But I totally get the usage now. That said, could you use InputOption::VALUE_IS_ARRAY instead of parsing it yourself? I'm not familiar enough with Symfony Console.

[hanneskod]

The reason to use array_filter is that explode(",", "") === [""] and not [] as one might expect. It is used in many places, so puting it in a method of its own sounds like a good idea. Done.

InputOption::VALUE_IS_ARRAY maked it possible to specify an option multiple times. So that instead of

scan src --ignore-paths=dir1,dir2

one would use

scan src --ignore-path=dir1 --ignore-path=dir2

The csv solution was already in place with include-rules and exclude-rules, thats why I opted for it here as well.

The latest commit removes the ignore-path and extension checks when the added path is a file name (as oposed to the result of a directory iteration). If you specify a file name to scan you simply want that file scanned...

[hanneskod]

If there are no more suggested changes I feel this is ready to merge.