* nto-tdep.h: Include osabi.h. Prototypes for generic Neutrino

* nto-tdep.h: Include osabi.h.  Prototypes for generic Neutrino
osabi sniffer, signal handling initializer, 'in_dynsym_resolve_code'
function and nto_set_target function.
(struct nto_target_ops): Put comments inline with struct.  Add osabi
sniffer hook.  Redefine macros to permit testing/assignment.  Remove
nto_ prefix from members.
* nto-tdep.c (nto_find_and_open_solib): Allocate all buffers
dynamically to support arbitrary root paths.  Check for basename of
lib in search path and then check for absolute.
(nto_in_dynsym_resolve_code): New function.
(nto_core_sniffer): New function.
(regset_core_fns): Register core sniffer.
(nto_initialize_signals): New function.
(_initialize_nto_tdep): Move signal initialization code to above to
avoid initialization race conditions.
(nto_set_target): New function.
* nto-procfs.c: Minor formatting/indenting changes.
(procfs_is_nto_target): New function.
(procfs_open): Set nto_is_nto_target.
(_initialize_procfs): Ditto.  Remove notice_signals() call to avoid
initialization race conditions.
(procfs_create_inferior): Resume inferior after creation.
* i386-nto-tdep.c: Declare i386_nto_target.
(init_i386nto_ops): Initialize i386_nto_target instead of
current_nto_target.
(i386nto_init_abi): Initialize signals.  Call nto_set_target.  Set
TARGET_SO_IN_DYNSYM_RESOLVE_CODE.
(_initialize_i386nto_tdep): Call init_i386nto_ops.  Register osabi sniffer.