MT#10383 Kamailio.init new action check-config and stop checking config on start

Change-Id: Ia534307c8152c0afbfda5931caab75772d24d12d
MT#9257 add new radius lib as an alternative for jessie build

Change-Id: I3f9149c780c99f288e99e34d288f5d46278bf91e
Imported Upstream version 4.2.1
Merge tag 'upstream/4.2.1'

Upstream version 4.2.1
Update debian changelog to 4.2.1-1

Change-Id: I235d3b9e696b4aea7e31e85420e0f017ab0237ce