Call setter on explicitly quoted strings.

Fixes #7.

decode.go

diff --git a/decode.go b/decode.go
index fd1ff96..75a2c42 100644
--- a/decode.go
+++ b/decode.go
@@ -283,12 +283,13 @@
 	var tag string
 	var resolved interface{}
 	if n.tag == "" && !n.implicit {
+		tag = "!!str"
 		resolved = n.value
 	} else {
 		tag, resolved = resolve(n.tag, n.value)
-		if set := d.setter(tag, &out, &good); set != nil {
-			defer set()
-		}
+	}
+	if set := d.setter(tag, &out, &good); set != nil {
+		defer set()
 	}
 	switch out.Kind() {
 	case reflect.String:

decode_test.go

diff --git a/decode_test.go b/decode_test.go
index 224e369..55db804 100644
--- a/decode_test.go
+++ b/decode_test.go
@@ -435,6 +435,8 @@
 	{"_: [1,A]", "!!seq", []interface{}{1, "A"}},
 	{"_: 10", "!!int", 10},
 	{"_: null", "!!null", nil},
+	{`_: BAR!`, "!!str", "BAR!"},
+	{`_: "BAR!"`, "!!str", "BAR!"},
 	{"_: !!foo 'BAR!'", "!!foo", "BAR!"},
 }
 
@@ -491,7 +493,7 @@
 	}()
 
 	m := map[string]*typeWithSetter{}
-	data := "{abc: 1, def: 2, ghi: 3, jkl: 4}"
+	data := `{abc: 1, def: 2, ghi: 3, jkl: 4}`
 	err := yaml.Unmarshal([]byte(data), m)
 	c.Assert(err, IsNil)
 	c.Assert(m["abc"], NotNil)