Wrap cjson in a namespace, and compile it as c++.

This is done so that we can compile cjson into remus and not have the
symbols clash when we link to another library using cjson.

Change-Id: I7a92c56e4a68e0fac880ad47614b763fbb554e81
Switch over to mesh workers file format to be json.

Change-Id: Ib5be53025ab108b9e334e171bdf7db0b9fea211e
Merge branch 'json_rw_files'

Change-Id: I8d11c18e18f7db8e9f71e1b064006d34a710aa6d