Refactor RecordConfig: Add getters/setters (#314)

* Replace RecordConfig.Name and .NameFQDN with getters and setters.
* Replace RecordConfig.Target with getters and setters.
* Eliminate the CombinedTarget concept.
* Add RecordConfig.PopulateFromString to reduce code in all providers.
* encode and decode name.com txt records (#315)
* Replace fmt.Errorf with errors.Errorf

models/quotes_test.go

@@ -0,0 +1,79 @@
+package models
+
+import (
+	"testing"
+)
+
+func TestIsQuoted(t *testing.T) {
+	tests := []struct {
+		d1 string
+		e1 bool
+	}{
+		{``, false},
+		{`foo`, false},
+		{`""`, true},
+		{`"a"`, true},
+		{`"bb"`, true},
+		{`"ccc"`, true},
+		{`"aaa" "bbb"`, true},
+	}
+	for i, test := range tests {
+		r := IsQuoted(test.d1)
+		if r != test.e1 {
+			t.Errorf("%v: expected (%v) got (%v)", i, test.e1, r)
+		}
+	}
+}
+
+func TestStripQuotes(t *testing.T) {
+	tests := []struct {
+		d1 string
+		e1 string
+	}{
+		{``, ``},
+		{`a`, `a`},
+		{`bb`, `bb`},
+		{`ccc`, `ccc`},
+		{`dddd`, `dddd`},
+		{`"A"`, `A`},
+		{`"BB"`, `BB`},
+		{`"CCC"`, `CCC`},
+		{`"DDDD"`, `DDDD`},
+		{`"EEEEE"`, `EEEEE`},
+		{`"aaa" "bbb"`, `aaa" "bbb`},
+	}
+	for i, test := range tests {
+		r := StripQuotes(test.d1)
+		if r != test.e1 {
+			t.Errorf("%v: expected (%v) got (%v)", i, test.e1, r)
+		}
+	}
+}
+
+func TestSetTxtParse(t *testing.T) {
+	tests := []struct {
+		d1 string
+		e1 string
+		e2 []string
+	}{
+		{`foo`, `foo`, []string{`foo`}},
+		{`"foo"`, `foo`, []string{`foo`}},
+		{`"foo bar"`, `foo bar`, []string{`foo bar`}},
+		{`foo bar`, `foo bar`, []string{`foo bar`}},
+		{`"aaa" "bbb"`, `aaa`, []string{`aaa`, `bbb`}},
+	}
+	for i, test := range tests {
+		ls := ParseQuotedTxt(test.d1)
+		if ls[0] != test.e1 {
+			t.Errorf("%v: expected Target=(%v) got (%v)", i, test.e1, ls[0])
+		}
+		if len(ls) != len(test.e2) {
+			t.Errorf("%v: expected TxtStrings=(%v) got (%v)", i, test.e2, ls)
+		}
+		for i := range ls {
+			if len(ls[i]) != len(test.e2[i]) {
+				t.Errorf("%v: expected TxtStrings=(%v) got (%v)", i, test.e2, ls)
+			}
+		}
+	}
+}