Fixes #1305

readline doesn't really handle when input comes from a file or pipe,
so only use readline if stdin is a tty.

Thanks to johnnyrun for a patch which was used for inspiration here.

Fixes #1314

The embedded jemalloc we ship is outdated and jemalloc is now
generally available in distributions, so stop shipping our own copy.

Fixes	#1312

See Also:	CVE-2013-4090

Correct what was wrong and describe obj.

We may have to retire it, it is quite flakey overall for reasons that
are not worth the bother to work around.

Feedback from dharrigan and bjorn

A-E is handled by varnish anyway and this is confusing

Add a -N option for use with utilities. This takes a VSM filename as argument, and will also disable the abandonment checks.

This allows reading a stale VSM file (e.g. _VSM.keep saved from a
panic) for forensics gathering.