Update to latest mgmt.git

In preparation for adding httpserver.so to mgmt module, update to latest
mgmt.git which fixes unsupported boost_program_options library
dependency to boost_program_options-mt.

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
Makefile: Add httpserver rule

The httpserver is part of the compilation of the mgmt.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
modules: Add httpserver.so to mgmt module

The httpserver.so is added to the image and will be
placed under /usr/mgmt

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>