The following environment variables allows several
setting by the environment:
* AFB_TRACEREQ, AFB_TRACEDITF, AFB_TRACESVC, AFB_TRACEEVT
These variables allows setting of options --tracereq,
--traceditf, --tracesvc, --traceevt
* AFB_LDPATHS
Set the option --ldpaths
Change-Id: I22700c658ce3fa1ceb15eab8f67adaaf41627b8f
Signed-off-by: José Bollo <jose.bollo@iot.bzh>