add docs: Installing Locust on Mac OS
Merge pull request #51 from yurtaev/patch-1

add docs: Installing Locust on Mac OS
Changed OS X instruction include only libevent.

It is recommended to use pip rather than Homebrew to manage Python dependencies.
Make locust compatible with Gevent 1.0 rc2. Should fix #53 and issues discussed in #49.
Added changelog entry and bumped version to 0.6.2
added run option indicating on which port to run web server
Merge pull request #54 from manova/port_argument

Added argument to options parser indicating on which port to run the web UI
Moved port int validation to optparse's add_option
Update docs/api.rst

world's most challenging fix. Line 71 currently reads "The `wollowing` event hooks..."
Changing to read "The following event hooks...." 
Merge pull request #55 from cbrinley/patch-1

Typo in docs/api.rst
Use msgpack for serializing data sent between Locust master nodes and slave nodes
Fixed compatibility issue with pyzmq 13.0.0