daemon-windows: Ability to handle windows service calls.

The following code does not add any users yet.

The visioned workflow that this piece of code should work with is:
* Create a windows service through a startup script with
a tool like 'sc'
ex:  sc create ovsdb-server binpath=
 "C:\openvswitch\usr\sbin\ovsdb-server.exe -vconsole:off
-vsyslog:off -vfile:info --remote=ptcp:6632:127.0.0.1 --log-file
--service-monitor --service"

* Start the service from the startup script.
ex: sc start ovsdb-server

* Terminate the service during shutdown process.
ex: sc stop ovsdb-server

* Abrupt termination will restart the service.

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
daemon-windows: Add users for windows services.

Start with ovs-vswitchd and ovsdb-server.

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Enhance userspace support for MPLS, for up to 3 labels.

This commit makes the userspace support for MPLS more complete.  Now
up to 3 labels are supported.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Co-authored-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Simon Horman <horms@verge.net.au>