[patch 0/4] timerfd c/r support, v4

Hi guys, here is an updated version of c/r support for timerfd files. The main change
is in how @ticks are restored in patch 3 -- I switched to ioctl code, which is wrapped
with CONFIG because I still think that while there is only one ioctl designated
solely for c/r needs no need to build it all the time until explicitly requested.
Please take a look once time permit. Comments are highly appreciated.
Also note the last patch is for man-page git repo, not for kernel.

Thanks!