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/match/contains.go

@@ -0,0 +1,58 @@
+package match
+
+import (
+	"fmt"
+	"strings"
+)
+
+type Contains struct {
+	Needle string
+	Not    bool
+}
+
+func NewContains(needle string, not bool) Contains {
+	return Contains{needle, not}
+}
+
+func (self Contains) Match(s string) bool {
+	return strings.Contains(s, self.Needle) != self.Not
+}
+
+func (self Contains) Index(s string) (int, []int) {
+	var offset int
+
+	idx := strings.Index(s, self.Needle)
+
+	if !self.Not {
+		if idx == -1 {
+			return -1, nil
+		}
+
+		offset = idx + len(self.Needle)
+		if len(s) <= offset {
+			return 0, []int{offset}
+		}
+		s = s[offset:]
+	} else if idx != -1 {
+		s = s[:idx]
+	}
+
+	segments := acquireSegments(len(s) + 1)
+	for i, _ := range s {
+		segments = append(segments, offset+i)
+	}
+
+	return 0, append(segments, offset+len(s))
+}
+
+func (self Contains) Len() int {
+	return lenNo
+}
+
+func (self Contains) String() string {
+	var not string
+	if self.Not {
+		not = "!"
+	}
+	return fmt.Sprintf("<contains:%s[%s]>", not, self.Needle)
+}