datepicker bootstrap

remove old jquery datepicker and replace it with a bootstrap one.

Notes:
- Had to add custom modification to the library to support the weeks number.
- The bootstrap datetimepicker library need moment.js in order to work
This line seems like a hack and result in calling two times .set('value'). When I tested, I had two set('value') with the same value passed each time, so I guess it's supposed to catch a special case I did not encountered ?