bprint macros go in vdef.h,  VCS_* in vcs.h

Remove srandomdev() look-alike, we already have a compat version

Eliminate libvarnish.h embedded #includes.

We now have
	<vapi/vs[mcl].h> for the programmatic API

	<vapi/vs[cl]_int.h> for the underlying structure,
			    shared between API and varnishd

the tbl/ subdirectory

This is based on output from some scripts and basic sanity testing.

and external files are included with <...>

crashing child to do so, and then explicitly start it again.