remove all (legacy) "i4b_" prefixes outside of sys/netisdn.
Prefix all card specific driver support files with the basename
of the driver bus attachement file.
Renamed here:
isapnp_isic.c -> isic_isapnp.c
i4b_ctx_s0P.c -> isic_isapnp_ctx_s0P.c
i4b_drn_ngo.c -> isic_isapnp_drn_ngo.c
i4b_dynalink.c -> isic_isapnp_dynalink.c
i4b_elsa_qs1i.c -> isic_isapnp_elsa_qs1i.c
i4b_siemens_isurf.c -> isic_isapnp_siemens_isurf.c
i4b_sws.c -> isic_isapnp_sws.c
i4b_tel_s0P.c -> isic_isapnp_tel_s0P.c