Use xcp-inventory package

Signed-off-by: John Else <john.else@citrix.com>
Add forkexec dependency

Signed-off-by: John Else <john.else@citrix.com>
Use standalone xen-api-client package

Signed-off-by: John Else <john.else@citrix.com>
Update OASIS

Signed-off-by: John Else <john.else@citrix.com>