SVGHMI: add "unsubscribable" property to widgets in order to generalize what already happens for jump buttons.
In most cases jump buttons do not really subscribe to pointed HMI variable, path is given as a relative page jump path. When widget.unsubscribable is set to true, no subscription is made on page switch, but still offset is updated.
This fixes bug happening on relative jump buttons without "disabled" element where offset did not change on relative page switch.
<?xml version="1.0"?>
<!-- generated by wxGlade 0.6.4 on Thu May 16 13:24:16 2013 -->
<application path="" name="" class="" option="0" language="python" top_window="wxglade_hmi" encoding="UTF-8" use_gettext="0" overwrite="0" use_new_namespace="1" for_version="2.8" is_template="0" indent_amount="4" indent_symbol="space" source_extension=".cpp" header_extension=".h">
<object class="Class_wxglade_hmi" name="wxglade_hmi" base="EditFrame">
<style>wxDEFAULT_FRAME_STYLE</style>
<title>frame_1</title>
<object class="wxStaticBoxSizer" name="sizer_1" base="EditStaticBoxSizer">
<orient>wxVERTICAL</orient>
<label>Wiimote Test</label>
<object class="sizeritem">
<flag>wxEXPAND</flag>
<border>0</border>
<option>0</option>
<object class="wxButton" name="button_1" base="EditButton">
<label>Connect Wiimote</label>
<events>
<handler event="EVT_BUTTON">OnConnectButton</handler>
</events>
</object>
</object>
<object class="sizeritem">
<flag>wxEXPAND</flag>
<border>0</border>
<option>0</option>
<object class="wxButton" name="button_2" base="EditButton">
<label>Disconnect Wiimote</label>
<events>
<handler event="EVT_BUTTON">OnDisconnectButton</handler>
</events>
</object>
</object>
<object class="sizeritem">
<flag>wxEXPAND</flag>
<border>0</border>
<option>0</option>
<object class="wxStaticText" name="label_1" base="EditStaticText">
<attribute>1</attribute>
<label>Status :</label>
</object>
</object>
<object class="sizeritem">
<flag>wxEXPAND</flag>
<border>0</border>
<option>0</option>
<object class="wxStaticText" name="label_2" base="EditStaticText">
<attribute>1</attribute>
<label>no status</label>
</object>
</object>
</object>
</object>
</application>