Date picker could be easier to style

[ekdahl]

The date picker has inline style for colors and borders and some elements (that should be styled) don't have classes.

Suggestion:

• Introduce a class for the div containing the date picker and remove the inline background color from that.
• Introduce a class for the td elements for the days from the adjacent month and remove the inline style.

PS. I know it's possible to override the inline styles etc., I just think there's room for improvement.