Rename Node2/node2 to Node/node in trunk

[Raymond Feng]

Hi,

We now have the Node APIs in the code base with 2 suffix, such as SCANode2, 
SCANode2Factory and tuscany-node2-api, tuscany-node2-impl. I propose that we 
rename them back to Node/node.

If there is no objection, I'll do it early next week.

Thanks,
Raymond