- For NT_X86_XSTATE we need a system elf.h
 - Drop duplicated parasite-syscall.h
 - Organize headers in the way
    - system headers
    - asm headers
    - regular headers
    - protobuf stuff
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>