Add possibility to ignore custom paths via arguments

[keradus]

... as without it, one cannot fully use the tool and has to host his own version of script with ignored paths hardcoded, like here: https://github.com/FriendsOfPHP/PHP-CS-Fixer/blob/2.11/check_trailing_spaces.sh#L10

First, shall be implemented directly in PHP CS Fixer repo, to show it works properly, and then backported into this dedicated repo

[keradus]

cc @julienfalque

[keradus]

@EvgenyOrekhov, perhaps with your ninja powers in shell, you could implement this feature please? :)

[EvgenyOrekhov]

@keradus I will take a shot at it when I have time!

[EvgenyOrekhov]

@keradus Sorry, I don't have the right skills to implement this feature.

[keradus]

damn, neither do us :(
thanks for giving it a try, highly appreciated !