Register content-service

BCCM currently fails since the added content-service is not registered.

This could simply be added by registering this in bccm, however there was discussion whether this name was too generic, see attached mail.

I notice a new module "content-service" has been added (channelmanager).
I suggest to consider using a more specific / less 'common' name than
"content-service" as that a) very likely will be confusing what purpose it has,
b) potentially conflict with a more generic future "content service".

Ate

-------- Forwarded Message --------
Subject:        [Hippo-dev] hippo-bccm-11.2-last-to-12.0-head (11.2.0 - 12.0.0-SNAPSHOT) - Build # 6 - Still Unstable!
Date:   Thu, 9 Mar 2017 00:50:31 +0100 (CET)
From:   Hippo Build Daemon <hippo-eng@bloomreach.com>
Reply-To:       Software development list <hippo-dev@lists.onehippo.org>
To:     hippo-dev@lists.onehippo.com, arent-jan.banck@bloomreach.com

1. ***Failed: com.onehippo.cms7.bccm.Bccm.write XML current diff: target/bccm-diff-current-modules.xml *

Detected 1 new, 0 modified, and 0 obsolete operations
new     : ins-node path="/hippo:configuration[1]/hippo:modules/content-service"