[CRIU] [RFC] Dropping plugins and fxsave code

[Cyrill Gorcunov]

Guys, while beeing rebasing various criu stuff I noted there are
a few things we can do to diet criu source code.

1) Drop plugins code. I suspect nobody use it and never used
   for something serious.

2) Require x86 xsave feature from scratch, old fxsave and such
   should be dropped off. After all it is 2018 already and I
   really doubt if anyone run criu on that old machines (which
   are about 10 years old from now).

What do you think?

	Cyrill