2013.03.25, Version 0.0.13
* force requests to go over http. Thanks Randal Truong

2013.01.24, Version 0.0.12
* track_charge() no longer includes $time by default, rather it lets
Mixpanel's servers set the time when they receive the transaction.  This
doesn't modify the ability for the user to pass in their own $time (for
importing transactions).

2013.01.11, Version 0.0.11

* added track_charge() method which provides the ability to record user
transactions for revenue analytics.
* added clear_charges() method which provides the ability to remove a
users transactions from Mixpanel
* added tests for delete_user()

2012.11.26, Version 0.0.10

* added import() method which provides the ability to import events
older than 5 days.  Contributions from Thomas Watson Steen.

2012.11.15, Version 0.0.9

* removed time from properties sent to server.  This is to ensure that
UTC is always used.  Mixpanel will set the correct time as soon as they
receive the event.

2012.10.24, Version 0.0.8

* added mp_lib property, so people can segment by library

2012.01.05, Version 0.0.7

* added unit tests
* people.increment() only prints error message if debug is true

2012.01.01, Version 0.0.6

* added engage support
	* people.set()
	* people.increment()
	* people.delete_user()

* deprecated old constructor: require("mixpanel").Client(token)

* added new constructor: require("mixpanel").init(token)
