Preserve descriptions and tags of fields containing embedded structures

Signed-off-by: Dmitry Zenovich <dzenovich@gmail.com>

Author: zenovich

fixtures/bugs/3125/item.go

@@ -0,0 +1,20 @@
+package _3125
+
+// swagger:model Item
+type Item struct {
+	// Nullable value
+	// required: true
+	// Extensions:
+	// ---
+	// x-nullable: true
+	Value1 *ValueStruct `json:"value1"`
+
+	// Non-nullable value
+	// required: true
+	// example: {"value": 42}
+	Value2 ValueStruct `json:"value2"`
+}
+
+type ValueStruct struct {
+	Value int `json:"value"`
+}