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/XmlHelper.h

@@ -0,0 +1,54 @@
+/* 
+ * File:   XmlHelper.h
+ * Author: SET - nmset@netcourrier.com
+ * License : LGPL version 2.1
+ * Copyright SET, M. D. - © 2014
+ *
+ * Created on December 15, 2019, 4:13 PM
+ */
+
+#ifndef XMLHELPER_H
+#define XMLHELPER_H
+
+#include <wx/wx.h>
+#include <wx/xml/xml.h>
+
+#define XML_ROOT_NAME _T("TABLE")
+#define XML_ROW_NAME _T("ROW")
+#define XML_ATTR_TYPE _T("Type")
+#define XML_ATTR_PREF _T("Preferred")
+#define XML_ATTR_NOTES _T("Notes")
+#define EMPTY_DOC _T("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<TABLE/>")
+
+/**
+ * Application helper to quickly get the Intent value.
+ * @param doc
+ * @param value
+ * @return 
+ */
+class XmlHelper
+{
+public:
+    
+    /**
+     * Parses value which is XML data and returns the XML root node, while
+     * loading the XML data in doc.
+     * If value does not have the expected tags defined above, returns NULL.
+     * @param doc
+     * @param value
+     * @return 
+     */
+    static wxXmlNode * ValidateXmlValue(wxXmlDocument& doc, const wxString& value);
+    /**
+     * Returns a valid Intent value or an empty string.
+     * @param xmlData
+     * @return 
+     */
+    static wxString GetIntent(const wxString& xmlData);
+private:
+    XmlHelper();
+    virtual ~XmlHelper();
+};
+
+#endif /* XMLHELPER_H */
+