Add bdb_bind, clean up init, s/Backend/BackendDB/

servers/slapd/back-bdb/Makefile.in

servers/slapd/back-bdb/add.c

servers/slapd/back-bdb/back-bdb.h

servers/slapd/back-bdb/backbdb.dsp

servers/slapd/back-bdb/compare.c

servers/slapd/back-bdb/config.c

servers/slapd/back-bdb/delete.c

servers/slapd/back-bdb/dn2entry.c

servers/slapd/back-bdb/dn2id.c

servers/slapd/back-bdb/id2entry.c

servers/slapd/back-bdb/init.c

servers/slapd/back-bdb/proto-bdb.h

servers/slapd/back-bdb/search.c