Refactored Belgium calendar to use DateTime objects; add doc-comment
Refactored France calendar to use DateTime objects; add doc-comment
Refactored Alsace Mosselle calendar to use DateTime objects; add doc-comment
Refactored for using objects; more doc-comments.
Fixed unittest for Netherlands calendar
Fixed unittest for Belgium calendar
Fixed unittest for France calendar
Fixed unittest for AlsaceMoselle calendar
Fixed unittest for AlsaceMoselle calendar