This function allows to connect to an API exported by the
binder.
The demo program afb-client-demo is modified to integrate
on option that direct API connection.
Example:
server: afb-daemon --ws-server unix:hello
client: afb-client-demo -d -H unix:hello
Change-Id: Id9f857a453c406df1c4b36eb25fb5e833a938c3d
Signed-off-by: José Bollo <jose.bollo@iot.bzh>