New runtime with relayfs and netlink checked in

[Martin Hunt]

I've checked in a huge update to the SystemTap runtime.  This uses
relayfs and/or netlink and is much different to use that the previous
version. Feedback is appreciated. There is a huge todo list but I have
been testing on i386 and x86_64 with up to 4 cpus and it works well. 

All the documentation is out-of-date; I'll be fixing it today.
Meanwhile, if you want to try it out... 

Update from CVS.

> cd stp/src/runtime
> cvs update -d
> cd relayfs
>./build
should build cleanly

>cd ../stpd
>make

>cd ../probes/shellsnoop
>./build
should build "dtr.ko" with some warnings about "relayfs_xxx"
undefined.  

> su
>./stp dtr.ko
Creating channel with 4 sub-buffers of size 8192.
Press Control-C to stop.

Now open a shell and type some commands.  You should see output
immediately in the stp window. Hit ^C when done.

That was using netlink I/O.  To use relayfs, edit dtr.c and comment out
the 5th line, "#define STP_NETLINK_ONLY" 
>./build
>./stp dtr.ko

Now open a shell and type lots of commands.  You will soon start seeing
output.  It will be blocky , timestamped, and per-cpu. Hit ^C to exit.
You should see data files, "stpd_cpuX" for each cpu in your system.

Martin