MBUS-1625: Use an environment variable to specify Linux static proximity instead of a config item

Change-Id: If6bc93130de4195deeb8b9a7656661877327ca2b
ALLJOYN-1626: Do not send empty string as Linux static proximity if there is no valid value to send

Change-Id: I27524fb583e4459ea449e17d05b1c603e1e47784
ALLJOYN-1635: SessionlessObj::SessionJoinedSignalHandler was using invalid key for changeIdMap

Change-Id: I01508eb79eaaa6e1729b9a75f7ec786b0d3fc956
ALLJOYN-1635: Changed SessionlessObj::FoundAdvNameSigHandler parsing of changeid from decimal to hex

Change-Id: Ib03fb721771cb5fd3925a21f0c404c76cb10c8dd