Re-align __set_state on DateTime method (briannesbitt#1172)

Merge pull request briannesbitt#1169 from Glavic/phpcs-fix

Fix for phpcs to pass

Merge pull request briannesbitt#1129 from kylekatarnls/remove-modify

Remove modify and fix diffInSeconds

Turns out travis doesn't have 5.3.6 ... removing specific 5.3.X versi…

…on, just test against the latest because of https://bugs.php.net/bug.php?id=52738

Merge pull request briannesbitt#395 from wangchj/master

Convenience methods isMonday(), ... isSunday()

Merge pull request briannesbitt#350 from localheinz/fix/unused-import

Fix: Remove unused import

Might as well make it public !

Fixed diffInSeconds() to obey TestNow value. Fixed up tests to pass w…

…hen close to time change.