use binaries instead of strings when cutting backtraces
use binaries instead of strings when cutting backtraces

Which should be faster and most importantly we still have issue with
memory consumption due to slow requests diagnostics.

Change-Id: I8cf03f4065922afc98e72d96ede247ba4a0ba8f4
Reviewed-on: http://review.membase.org/6202
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Tested-by: Dale Harvey <491ccac09a36ad1e38b698f273b84fd8efc31071@arandomurl.com>
Reviewed-by: Dale Harvey <491ccac09a36ad1e38b698f273b84fd8efc31071@arandomurl.com>

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