LIBCLOUD-615: Add optional param project for ex_list_networks() to CloudStack provider.

Signed-off-by: René Moser <mail@renemoser.net>
Signed-off-by: Sebastien Goasguen <runseb@gmail.com>

This closes #367
CLOUDSTACK: option to start VM in a STOPPED state

Signed-off-by: Sebastien Goasguen <runseb@gmail.com>

This closes #368
CLOUDSTACK: ex_list_nics, ex_add_nic_to_vm, ex_remove_nic_from_vm + tests