MB-9451: deallocate memory sooner while sending diags
MB-9451: deallocate memory sooner while sending diags

We're now doing parts of pretty-printing work in separate short-lived
processes. The idea is that when those processes die, their memory is
released immediately.

Change-Id: I63dd276bae10f26661011dc748a8b04095b887cf
Reviewed-on: http://review.couchbase.org/31694
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Reviewed-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>

daverigby/ns_server,daverigby/ns_server,nimishzynga/ns_server,ceejatec/ns_server,ceejatec/ns_server,ceejatec/ns_server,nimishzynga/ns_server,membase/ns_server,nimishzynga/ns_server,daverigby/ns_server,membase/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,mschoch/ns_server,membase/ns_server,membase/ns_server,ceejatec/ns_server,mschoch/ns_server,mschoch/ns_server,t3rm1n4l/ns_server,daverigby/ns_server,daverigby/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,nimishzynga/ns_server,mschoch/ns_server,mschoch/ns_server,ceejatec/ns_server,membase/ns_server,nimishzynga/ns_server,mschoch/ns_server,membase/ns_server,t3rm1n4l/ns_server,t3rm1n4l/ns_server