Drivers get_name method should be const

There is no point in returning a const object as a name, it is useful to
make the method const.

This patch changes hw_driver from
virtual const std::string get_name() to virtual std::string get_name() const

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
libtools should be added to the image

libtools got its own module and was added as a dependency to the
httpserver model.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>