In this commit xSupportComponent is no longer derived from attachable
model of AOMD. This make it more general.

In the same spirit the friend class xPhysDomain is removed. It was
intended to avoid some component creation in instance of
xSupportComponent by anything but xPhysDomain. Now the method is made
public and  xSupportComponent instance can be modified.

As this class is a key feature of future mesh tool chain this
generalization was mandatory to fit to : A block of the tool chain
provide a service to access support component via a functor that return
const xSupportComponent.

This functor type is now given by xSupportComponent.h header.(TODO
must replace some typdef in xDoubleCut)

xDoubleCut has to be modified accordingly. Now in xPhysDomain class
use of tag for xSupportComponent is replaced by
xAttachedDataManagerAOMDGeneric mechanism. Not that knowsupportcomponent
member is suppressed and its action treated via the new usage of
xAttachedDataManagerAOMDGeneric.
Note also that update with change of definition is now dealing
correctly with support (see dom5 in disk example which is now cleanly
updated)