ssa.c: Don't close upstream connection, if IBV_EVENT_CLIENT_REREGISTER is received.

 The change allows an SM failover/handover investigation.
 The behavior could be changed in future.
ssa.c, common.h: Add log_data1 buffer.

 It will be used for log printing where two gids should be
 printed.
ssa.c, core.c: Add parent_gid field to join query.

 Old parent will be taken into account in distribution tree
 building.
common.h,ssa_mad.h,core.c,ssa.c: Return parent type in response to join request.

 The parent's node type will be used in SM resiliancy feature.
 To struct ssa_svc two new fields are added: primary_type,
 secondary_type. At the moment, SSA supports only primary parent.
 secondary_type will be used in future.