WIP Add a dateAccuracyJoiner refinery

* derived from dateJoiner
WIP Add a dateAccuracyJoiner refinery

* derived from dateJoiner
Completed date accuracy joiner including tests
Merge branch 'dateAccuracyJoiner' of https://github.com/kehh/providence into dateAccuracyJoiner

Conflicts:
	app/refineries/dateAccuracyJoiner/dateAccuracyJoinerRefinery.php
Remove comment
Merge pull request #27 from kehh/dateAccuracyJoiner

Date accuracy joiner