Add the ability to access binding through tcp

This commit introduce "tcp", a new type of
provided/required api. It appears in the config.xml
as below:

  <urn:AGL:widget:provided-api>
    <param "name"="HOST:PORT/API" "value"="tcp">

  <urn:AGL:widget:required-api>
    <param "name"="HOST:PORT/API" "value"="tcp">

This implementation is a draft. The service
exposed can not start automatically. Use it
with the permission urn:AGL:permission::system:run-by-default.

Change-Id: Ic593f0d891692ca0c777c49057ec54c37fc55cc0
Signed-off-by: José Bollo <jose.bollo@iot.bzh>