Support of "!" quantifier for data file filters

[devolonter]

In some cases it is necessary to allow all files, but exclude some. This patch allows to use “!” symbol for negative pattern.

Usage example: #IMAGE_FILES = "*.png|*.jpg|!*@hd.png|!*@hd.jpg"

[blitz-research]

Ok, finally got around to looking at this.

A couple of issues:

• The recursion means 'path' can end up with a '//' prefix, which would probably cause a '!/blah' absolute path pattern to fail.
• Only the last '!" pattern has any effect.

I've committed my own version of this with the basic 'rules':

• If path matches any '!' pattern, return false; else if path matches any non-'!' pattern return true; else return false.

Not sure if they're 'good' rules though - what do you think?

[devolonter]

I should have done more tests, sorry… Your basic rules do exactly the same what I wanted to do in my version. Also it seems that your version will work a little bit faster. So I think your version is the best solution. Thanks for that!