Correct vzps usage

Conflicts:
	libpromises/cf3.extern.h
	libpromises/cf3globals.c
	libpromises/classes.c
	libpromises/processes_select.c

(cherry picked from commit 2bfcc5db3d7346ed864c32e4d7c9dc4ea97e9e56)
Correct test for openvz support

(cherry picked from commit ada8e7c0cb9d95f573ba283046d25b9b33963910)
UMR-fix: EvalContext's ->pass was unset by default.

There's logging code (PromiseBanner) that reports the pass and
valgrind reported it as an uninitialized memory read.  So change
EvalContextNew() to use calloc and ditch a bunch of initializations
to NULL and false that this does for us.

(cherry picked from commit f8aa78dfcfe1ab327a94907b82057049cfe78a8c)

Conflicts:
	libpromises/eval_context.c
Releasing 3.6.3 Release Candidate.