1.0 by Simon Monk
Library as downloaded 02Feb2012 22:55 UTC from http://srmonk.blogspot.com/2012/01/arduino-timer-library.html

1.1 by Jack Christensen
Changed data types of variables and functions:
 o event types and indexes changed from int to int8_t.
 o periods and durations changed from lon to unsigned long.
 o update() and stop() functions typed as void, since they return nothing.
 o pin numbers and pin values changed from int to uint8_t, this agrees with digitalWrite().
 o added return values to Timer::pulse() and Timer::oscillate(uint8_t, unsigned long, uint8_t).
 o changed test in Event::update() to use subtraction to avoid rollover issues.
 o Updated keywords.txt file to include all functions.

1.2 by Damian Philipp
 o Added a range check to Timer::stop() to avoid memory corruption.
 o Added constants to <Timer.h>: 
    - NO_TIMER_AVAILABLE: Signals that while an event was to be queued, no free timer could be found.
    - TIMER_NOT_AN_EVENT: Can be used to flag a variable that *might* contain a timer ID as *not*
      containing a timer ID
 o Replaced a bunch of magic numbers in <Timer.cpp> by the above constants
 o Added several comments
 o Added Timer::pulseImmediate(). pulseImmediate sets the pin to the specified value for the given
   duration. After the duration, the pin is set to !value.
   
1.3 by Jack Christensen
 o Added "blink2" example illustrating flashing two LEDs at different rates.
 o 19Oct2013: This is the last v1.x release. It will continue to be available on GitHub
   as a branch named v1.3. Future development will continue with Sandy Walsh's v2.0 which
   can pass context (timer ID, etc.) to the callback functions.
   
2.0 by Sandy Walsh
 o Added a "context" parameter to callbacks. You can pass in the context
   when the event is created and it will be sent back to callback when
   called. If you don't have any context data you want to pass in (let's
   say you're using separate callbacks for each timer), you can just
   pass in 0 and ignore it in the callback.