MB-100: feed binaries to ns_log for some memory savings
MB-100: feed binaries to ns_log for some memory savings

I've seen some avalance of crashes that we log into ns_log,
overloading ns_log quite easily. Part of that was some uneeded error
logging to standard output which is fixed in another commit. But I
also saw that ns_log doesn't store it's messages very
efficiently. I.e. it's using stringish-iolists (mostly lists of chars
with occasional atoms). Clearly, converting it to more efficient
iolist is a win.

Change-Id: Iabdd2aff36c66ed56400120fa775e723b4b1810b
Reviewed-on: http://review.couchbase.org/25574
Reviewed-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>

nimishzynga/ns_server,daverigby/ns_server,nimishzynga/ns_server,mschoch/ns_server,t3rm1n4l/ns_server,nimishzynga/ns_server,vzasade/ns_server,t3rm1n4l/ns_server,pavel-blagodov/ns_server,t3rm1n4l/ns_server,pavel-blagodov/ns_server,mschoch/ns_server,mschoch/ns_server,pavel-blagodov/ns_server,mschoch/ns_server,ceejatec/ns_server,daverigby/ns_server,daverigby/ns_server,nimishzynga/ns_server,ceejatec/ns_server,ceejatec/ns_server,mschoch/ns_server,vzasade/ns_server,membase/ns_server,t3rm1n4l/ns_server,vzasade/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,vzasade/ns_server,membase/ns_server,nimishzynga/ns_server,ceejatec/ns_server,daverigby/ns_server,pavel-blagodov/ns_server,membase/ns_server,membase/ns_server,membase/ns_server,membase/ns_server,mschoch/ns_server,nimishzynga/ns_server,daverigby/ns_server,ceejatec/ns_server