bundle qson lib in util (#1561)

* copy qson from https://github.com/joncalhoun/qson
  as author not want to maintain repo
* latest code contains our fix to proper decode strings
  with escaped & symbol
* replace package in api/handler/rpc

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

util/qson/merge_test.go

@@ -0,0 +1,37 @@
+package qson
+
+import "testing"
+
+func TestMergeSlice(t *testing.T) {
+	a := []interface{}{"a"}
+	b := []interface{}{"b"}
+	actual := mergeSlice(a, b)
+	if len(actual) != 2 {
+		t.Errorf("Expected size to be 2.")
+	}
+	if actual[0] != "a" {
+		t.Errorf("Expected index 0 to have value a. Actual: %s", actual[0])
+	}
+	if actual[1] != "b" {
+		t.Errorf("Expected index 1 to have value b. Actual: %s", actual[1])
+	}
+}
+
+func TestMergeMap(t *testing.T) {
+	a := map[string]interface{}{
+		"a": "b",
+	}
+	b := map[string]interface{}{
+		"b": "c",
+	}
+	actual := mergeMap(a, b)
+	if len(actual) != 2 {
+		t.Errorf("Expected size to be 2.")
+	}
+	if actual["a"] != "b" {
+		t.Errorf("Expected key \"a\" to have value b. Actual: %s", actual["a"])
+	}
+	if actual["b"] != "c" {
+		t.Errorf("Expected key \"b\" to have value c. Actual: %s", actual["b"])
+	}
+}