Added classes to manage simple tabular data of known structure using a

popup containing a wxGrid object.

BasePicker : Abstract class adding a popup to wxPickerBase  styled with
a wxTextCtrl.
BaseGridPicker : Abstract class adding a wxGrid in the popup.

JsonGridPickerCtrl : UI control storing the tabular data in a JSON
array.
LBoundJsonGridPicker : connect JsonGridPicker to database.
LGridJsonCellEditor : use LBoundJsonGridPicker in other wxGrid objects.
LGridJsonCellRenderer : render cell JSON data.

XmlGridPickerCtrl : UI control storing the tabular data in as XML
document.
LBoundXmlGridPicker : connect XmlGridPicker to database.
LGridXmlCellEditor : grid editor for LBoundXmlGridPicker.
LGridXmlCellRenderer : grid renderer for LBoundXmlGridPicker.

JsonHelper and XmlHelper : for applications to quickly get intent value
from database data..

The structure of managed tabular data :

Column 1 : Intent - this is what we want to store/edit. This can be
telephone numbers, email addresses, instant messaging addresses...
any single line piece of information that can exist many times for one
entity (person, company...).
Column 2 : Type - A short description of the intent : 'Home, Work,
Mobile, Fax, Other...'. It is displayed in a non editable wxComboBox.
Column 3 : Preferred - One line of data can be selected as the preferred
one. It is not mandatory, but it must be a single choice.
Column 4 : Notes - single line notes.

Adjust sql scripts and L7.dox.
Applied ANSI formatting style to all files.

Other changes :

Work around a nasty misbehavior.
Grid columns edited by a translated combobox expect full string
data as cell values. LResultSet::BEData() will report these mapped strings,
instead of database real data. LBoundComboBox::IsDirty() will always be
true even if the editor is unchanged once created.
Simplest workaround : disconnect m_BoundComboBox if unchanged.

LGridTextEditor::ProvideFormEditor() : set the form editor's value
explicitely.; wxTextCtrl does not interpret data it receives

LBoundControl::SetNull must be void.

LBoundGrid : Unbind:: instructions should limit to the widget's id, like Bind::

LConnection::GetReturnedKeys should return NULL.
LConnection::SetData should return void.

Notes : wxJSON must be configured with the same prefix as wxWidgets,
here /usr/local/{wxWidgets,wxWidgets-Release}.

L7/special/JsonHelper.cpp

@@ -0,0 +1,53 @@
+/* 
+ * File:   JsonHelper.cpp
+ * Author: SET - nmset@netcourrier.com
+ * License : LGPL version 2.1
+ * Copyright SET, M. D. - © 2014
+ * 
+ * Created on December 16, 2019, 8:25 PM
+ */
+
+#include "JsonHelper.h"
+#include <wx/jsonreader.h>
+
+JsonHelper::JsonHelper()
+{
+}
+
+JsonHelper::~JsonHelper()
+{
+}
+
+wxString JsonHelper::GetIntent(const wxString& jsonData)
+{
+    if (jsonData.IsEmpty())
+        return wxEmptyString;
+    
+    wxJSONReader reader(wxJSONREADER_STRICT);
+    wxJSONValue root;
+    uint nbErr = reader.Parse(jsonData, &root);
+    if (nbErr > 0)
+    {
+        const wxArrayString& errors = reader.GetErrors();
+        for (int i = 0; i < nbErr; i++)
+        {
+            wxASSERT_MSG(nbErr == 0, errors[i]);
+        }
+        return wxEmptyString;
+    }
+    if (!root.IsArray())
+    {
+        wxASSERT_MSG(root.IsArray(), _("JSON data is not an array"));
+        return wxEmptyString;
+    }
+    for (uint row = 0; row < root.Size(); row++)
+    {
+        if (root[row]["Preferred"].IsValid()
+                && !root[row]["Preferred"].AsString().IsEmpty()
+                && root[row]["Preferred"].AsInt() != 0)
+        {
+            return root[row]["Intent"].AsString();
+        }
+    }
+    return wxEmptyString;
+}