cleans up CakeTime::timeAgoInWords and adds option for custom futures string
fixes failing test cases from last CakeTime::timeAgoInWords changes

at b96eb1fb46e2cbd9f2917a8f4e63a4ecf3e569fd
code formatting, fixes PHPCS errors
Merge pull request #4780 from Schlaefer/timeAgoInWords-futureString

adds option for future string to CakeTime::timeAgoInWords & code cleanup