Be able to post JSON data to the ForeignSources ReST Service.

Tested on my working environment, and works perfect.
fix NMS-6587 badly formed addresses can be accepted as critical path IP
Merged a lot of lint fixes from the mrlambeth-master branch.
NMS-6587 forgot that an empty field is legitimate
Merge branch 'master' of github.com:OpenNMS/opennms
fix NMS-6588 path outage problems for IPv6
start (non-working) of a paged table directive
Merge remote-tracking branch 'origin/master' into features/ngui