Switch to metadata.json for Puppet forge releases

Since puppet 3.x, Puppet Labs Forge accept only the metadata.json file
for module description (Modulefile is now deprecated).

This patch :
 - convert the Modulefile to metadata.json.
 - bump major version to 1 (for juno).
 - switch to stackforge namespace.
 - bump vswitch module to 1.0.0 (semver release)

Change-Id: I13cba8a954215a42551963a8fdbeb387706b0e91