PFW: Virtual subsystems

BZ: 14587

- Added the possibility to declare parameters which have no real hardware
implementation. They are only intended to configure the hosting platform.
- A new subsystem type "Virtual" has been introduced to support those
hardwareless parameters.
- Virtual subsystems need no Mapping declaration in the structure
description

Change-Id: I44115f0dd0a26af74a544c6f08473b200aad94d3
Signed-off-by: Patrick Benavoli <patrickx.benavoli@intel.com>
Reviewed-on: http://android.intel.com:8080/25405
Reviewed-by: Barthes, FabienX <fabienx.barthes@intel.com>
Tested-by: Barthes, FabienX <fabienx.barthes@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>
diff --git a/parameter/ConfigurableElement.cpp b/parameter/ConfigurableElement.cpp
index b11b84f..c5d97f8 100644
--- a/parameter/ConfigurableElement.cpp
+++ b/parameter/ConfigurableElement.cpp
@@ -173,7 +173,7 @@
     return pChild->getValue(pathNavigator, strValue, parameterContext);
 }
 
-// Used for simulation only
+// Used for simulation and virtual subsystems
 void CConfigurableElement::setDefaultValues(CParameterAccessContext& parameterAccessContext) const
 {
     // Propagate to children