Minor tweaks to README.

README

@@ -92,7 +92,7 @@ These flags include:
 * UDP performance: iperf2/iperf3 both only are only about 50% as fast
 as nuttcp in UDP mode.  We are looking into this, but in the meantime,
 if you want to get UDP above 5Gbps, we recommend using nuttcp instead
-(http://www.nuttcp.net/)
+(http://www.nuttcp.net/).
 
 * Interval reports on high-loss networks: The way iperf3 is currently
 implemented, the sender write command will block until the entire
@@ -103,7 +103,7 @@ determine the best solution to this, but in the meantime, try using a
 smaller block size if you get strange interval reports.  For example,
 try "-l 4K".
 
-* -Z flag on OSX sometimes hangs
+* The -Z flag sometimes hangs on OSX.
 
 * On OpenBSD, the server seems to require a "-4" argument, implying
 that it can only be used with IPv4.