Update When.php

Minor bugfix: if a count is set as part of the RRULE, the internal counter needs to be reset, otherwise no new dates are returned.
Merge pull request #12 from UltraSimplified/master

Reset internal counter when a COUNT rule is specified
Make valid_date() public
Merge pull request #13 from JoeAnzalone/patch-1

Make valid_date() public
Fix for origin issue: #8, FREQ=MONTHLY Rrule breaks.
Merge pull request #15 from deldreth/master

Issue #8, FREQ=MONTHLY Rrule not working
Changed structure to support PSR-0 style autoloading
Update styling to PSR-2 standards
Added composer.json
Added phpunit.xml to root for running tests
Merge pull request #1 from ryakad/master

Modernize
Added travis
Merge pull request #2 from ryakad/master

Added travis