lib/ignore: Replace lib/fnmatch with github.com/gobwas/glob

Because it's literally ten times faster:



	benchmark                  old ns/op     new ns/op     delta

	BenchmarkMatch-8           13842         1200          -91.33%

	BenchmarkMatchCached-8     139           147           +5.76%



	benchmark                  old allocs     new allocs     delta

	BenchmarkMatch-8           0              0              +0.00%

	BenchmarkMatchCached-8     0              0              +0.00%



	benchmark                  old bytes     new bytes     delta

	BenchmarkMatch-8           12            0             -100.00%

	BenchmarkMatchCached-8     0             0             +0.00%

vendor/github.com/gobwas/glob/cmd/globdraw/main.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"github.com/gobwas/glob"
+	"github.com/gobwas/glob/match"
+	"github.com/gobwas/glob/match/debug"
+	"os"
+	"strings"
+	"unicode/utf8"
+)
+
+func main() {
+	pattern := flag.String("p", "", "pattern to draw")
+	sep := flag.String("s", "", "comma separated list of separators characters")
+	flag.Parse()
+
+	if *pattern == "" {
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	var separators []rune
+	if len(*sep) > 0 {
+		for _, c := range strings.Split(*sep, ",") {
+			if r, w := utf8.DecodeRuneInString(c); len(c) > w {
+				fmt.Println("only single charactered separators are allowed")
+				os.Exit(1)
+			} else {
+				separators = append(separators, r)
+			}
+		}
+	}
+
+	glob, err := glob.Compile(*pattern, separators...)
+	if err != nil {
+		fmt.Println("could not compile pattern:", err)
+		os.Exit(1)
+	}
+
+	matcher := glob.(match.Matcher)
+	fmt.Fprint(os.Stdout, debug.Graphviz(*pattern, matcher))
+}