Changes in 423fd49: gnu-sed add in wiki for mac

				wiki/howto/onboarding.md
			
          @@ -251,7 +251,7 @@ Install the GWT Browser Plugin for the GWT Development mode. As of 2016-08-31 Fi

           ### Create Hudson Job

           If you want a hudson job to run when you push your branch then you can run a script in `configuration` called . Run options for a branch titled `createHudsonJobForBug.sh`. For you bug branch titled `bug<bug number>`, create a build job, which will create a release, by running the script like so: `./createHudsonJobForBug.sh <bug number>`.

          -If on Windows, you may need to disable any web shields in antivirus software, to allow `curl` to function.

          +If on Windows, you may need to disable any web shields in antivirus software, to allow `curl` to function. If on Mac, you may need to install gnu-sed.

           ###Issues when playing around with AWS

           - The problem: **aws cli (used for aws ec2 describe-tags) hangs in eu-west-2** in all AZs on new instances I created, using a target group which permitted all outbound connections and inbound https, http and ssh connections. I tried permitting everything but that didn’t work. When I attached (at Axel’s suggestion) the Java Application with Reverse Proxy security group, it worked but — even if I duplicated this security group, and applied that copy instead — it still didn’t work.

...	...	@@ -251,7 +251,7 @@ Install the GWT Browser Plugin for the GWT Development mode. As of 2016-08-31 Fi
251	251
252	252	### Create Hudson Job
253	253	If you want a hudson job to run when you push your branch then you can run a script in `configuration` called . Run options for a branch titled `createHudsonJobForBug.sh`. For you bug branch titled `bug<bug number>`, create a build job, which will create a release, by running the script like so: `./createHudsonJobForBug.sh <bug number>`.
254		-If on Windows, you may need to disable any web shields in antivirus software, to allow `curl` to function.
	254	+If on Windows, you may need to disable any web shields in antivirus software, to allow `curl` to function. If on Mac, you may need to install gnu-sed.
255	255
256	256	###Issues when playing around with AWS
257	257	- The problem: aws cli (used for aws ec2 describe-tags) hangs in eu-west-2 in all AZs on new instances I created, using a target group which permitted all outbound connections and inbound https, http and ssh connections. I tried permitting everything but that didn’t work. When I attached (at Axel’s suggestion) the Java Application with Reverse Proxy security group, it worked but — even if I duplicated this security group, and applied that copy instead — it still didn’t work.