Preserve Unicode in JSON conversion

Unicode text should be saved as Unicode in saved Json files.
Closes #30

Version Control.accda.src/modules/clsOptions.bas

@@ -321,4 +321,7 @@ Private Sub Class_Initialize()
     ' Load default values
     Me.LoadDefaults
 
+    ' Other run-time options
+    JsonOptions.AllowUnicodeChars = True
+
 End Sub

Version Control.accda.src/modules/modJsonConverter.bas

@@ -153,6 +153,9 @@ Private Type json_Options
 
     ' The solidus (/) is not required to be escaped, use this option to escape them as \/ in ConvertToJson
     EscapeSolidus As Boolean
+
+    ' Allow Unicode characters in JSON text. Set to True to use native Unicode or false for escaped values.
+    AllowUnicodeChars As Boolean
 End Type
 Public JsonOptions As json_Options
 
@@ -724,9 +727,14 @@ Private Function json_Encode(ByVal json_Text As Variant) As String
         Case 9
             ' tab -> 9 -> \t
             json_Char = "\t"
-        Case 0 To 31, 127 To 65535
+        Case 0 To 31
             ' Non-ascii characters -> convert to 4-digit hex
             json_Char = "\u" & VBA.Right$("0000" & VBA.Hex$(json_AscCode), 4)
+        Case 127 To 65535
+            ' Unicode character range
+            If Not JsonOptions.AllowUnicodeChars Then
+                json_Char = "\u" & VBA.Right$("0000" & VBA.Hex$(json_AscCode), 4)
+            End If
         End Select
 
         json_BufferAppend json_Buffer, json_Char, json_BufferPosition, json_BufferLength