Revert "Modal option added"

This reverts commit dc0d9f480c3b335d47e61275d585bb30804a18ce.
Test: Options: beforeShowDay to non-UTC

The date passed to beforeShowDay is local. In GMT+ timezones, the tests
fail because date.getUTCDate() returns the day before it should.
Revert "Test: Options: beforeShowDay to non-UTC"

This reverts commit 2049f10d44567d3a7a300d7c8d3f2485db3804fe.
Test: Options: beforeShowDay to non-UTC

The date passed to beforeShowDay is local. By using UTC-times, the test
fails in GMT+ timezones.
Modal option added

'modal' option: can be either a function or a media query as a string.
If the function returns true or the media query matches, the datepicker
instead covers the entire screen and prevents phone keyboard popup (not
on WP8). Media queries relies on window.matchMedia. Ignores the
string-option if this is unavailable.
setDefaults added

$.fn.datepicker.setDefaults extends the default object.
Ignore deleted screenshots
setDefaults

Extend defaults instead of creating new object
Select button option added

Select button that closes the datepicker. Uses localization label
'select' if one or more dates are selected, otherwise the 'close' label.
Option can be true, false or 'modal' to only show the button when in
modal-mode.
Select button: Danish language support added