know if and when an unimplemented or obsoleted syscall is being used. Make the
message more end-user friendly.
And as long as we're here, rename some unimplemeted syscalls (linux_phys ->
linux_umount2, linux_vm86 -> linux_vm86old, linux_new_vm86 -> linux_vm86).
Change prototype for linux_newuname from `struct linux_newuname_t *' into
`struct linux_new_utsname *'. This change is reflected in linux.h and
linux_misc.c.
Lastly, make line-continuation and indentation more uniform.