kamailio - version bump to 4.2.0

new in sub-packages:

 kamailio:        rtpproxy-ng renamed to rtpengine
 kamailio-extras: tsilo jsonrpc-s
 kamailio-uuid:   new (uuid module)
 kamailio-ev:     new (evapi module)
main/kamailio: build fixes

- add missing checksum
- pass EMBEDDED_UTF8_DECODE to both 'make all' and 'make install'