Use year when calculating number of days in a month

Year number is needed for leap day calculation to work
Fix leap year calculation

Years divisible by 400 *are* leap years (iow: 2/29/2000 was on Tuesday)
see: http://en.wikipedia.org/wiki/Leap_year#Algorithm
Makefile: Calendar -> calendar, Days -> days

calendar.js and days.js needs to be lowercase for `make` to work on case
sensistive file systems
fix example - `two` is not defined

use `small` and `large` calendars in event listeners for `one` calendar
Merge pull request #22 from code42day/leap-year

Leap year
Merge pull request #23 from code42day/infastructure-fixes

Infastructure fixes