serf now does show the payload of events in the log

In the docs, it says that the event payload is not shown in the log. Using v0.2.1 it does, so I removed this paragraph.
Point OSX users to the fix they need to run before joining agents.

This info about the fix exists on the website, but isn't pointed to in the quickstart. I think a lot of users will be using OSX to try serf out, and it's confusing when it doesn't work as explained in the quickstart.
Merge pull request #60 from dustinmm80/patch-2

Point OSX users to the fix they need to run before joining agents.
Merge pull request #59 from dustinmm80/patch-1

website: serf now does show the payload of events in the log