fix remaining IPC_64 issue (shmctl)

also cleanup cruft related to the issue

numerous fixes to sysv ipc

some of these definitions were just plain wrong, others based on
outdated ancient "non-64" versions of the kernel interface.

as much as possible has now been moved out of bits/*

these changes break abi (the old abi for these functions was wrong),
but since they were not working anyway it can hardly matter.

consistency: change all remaining syscalls to use SYS_ rather than __NR_ prefix

global cleanup to use the new syscall interface

initial check-in, version 0.5.0