Remove serialize

As ask in Issue https://github.com/GordonLesti/Lesti_Fpc/issues/60 here are my changes to remove serialize functions.

After installing this new changes make sure to flush the caches.

I'll also removed some duplicated code.

Thanks for merging!
I've bet the whole time with myself that no one will ask that question ... 8-)

Because in January 19, 2038, at 03:14:08 UTC the buffer overflow for the unix timestamp (int32) will happen.