The lower level Lb/SCCP interface conn handling is essentially a copy of
OsmoMSC's A/SCCP infrastructure (OsmoMSC also connects to multiple BSCs).
The smlc_subscr is mostly a copy of OsmoBSC's bsc_subscr.
smlc_loc_req FSM is the SMLC side of OsmoBSC's new lcs_loc_req FSM.
cell_locations configures geographic coordinates of individual cells.
Change-Id: I917ba8fc51a1f1150be77ae01e12a7b16a853052