implement 'unit_base' option to select between KB and Kbit et. al.

With network testing, it's often desirable to measure in terms of
kilobits/megabits rather than kilobytes/megabytes. This adds an option named
'unit_base' which can be set to either '1' or '8', where '1' means represent in
terms of bits and '8' means to represent rate in terms of bytes.

Signed-off-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/engines/net.c b/engines/net.c
index 624ff15..31f7151 100644
--- a/engines/net.c
+++ b/engines/net.c
@@ -970,7 +970,7 @@
 	.options		= options,
 	.option_struct_size	= sizeof(struct netio_options),
 	.flags			= FIO_SYNCIO | FIO_DISKLESSIO | FIO_UNIDIR |
-				  FIO_PIPEIO,
+				  FIO_PIPEIO | FIO_BIT_BASED,
 };
 
 static int str_hostname_cb(void *data, const char *input)