function filterFileList(compiledFilter, files) {
        if (!compiledFilter) {
            return files;
        }

        var re = new RegExp(compiledFilter);
        return files.filter(function (f) {
            return !re.test(f.fullPath);
        });
    }
Returns a copy of 'files' filtered to just those that don't match any of the exclusion globs in the filter.

@param {?string} compiledFilter  'Compiled' filter object as returned by compile(), or null to no-op
@param {!Array.<File>} files
@return {!Array.<File>}