tennames, numstr): Replace by static local variables in their only
user.
(relates): Move from global/misc.c to common/nat.c.
(att_mode): Move from global/misc.c to subs/attsub.c.
thread entrypoints:
(lwpSelect, shutdown_sequence): Parameters didn't match thread entry
point prototype.
(lwpEntryPoint): Arguments didn't match thread entry point prototype.
Change linkage of functions without prototype declaration to static
where possible.
Remove some superflous declarations, replace others by suitable
includes.
