Make it possible to pass a pointer to the new value to ObjSetattr()
Put stats directly in vfp_ctx
Move ESI parser from a struct busyobj to struct vfp_ctx
Eliminate unused arguments.
Add the objcore to the vfp_ctx
More reduction of vfp_ctx->bo usage
Isolate length manipulations of objects.
Push space allocation for objects into cache_obj.c as well.
Pass the right string to syslog()

Fixes #1574
Eliminate the body from vfp_ctx, we now only manipulate it through
the objcore.
Push the last bit of struct object firmly into stevedore-space.