Updated Bootstrap Datepicker to 1.3.0
Update files for new datepicker

- Updated HTML where the datepicker is used
- Fixed JS function in scripts.js which was interfering with the new datepicker
- Removed readonly markings
- Fixes #54: Calendar overlap issue
merged datepicker CSS to style.css
Import datepicker.css in style.scss
Merge remote-tracking branch 'invoiceplane/development' into datepicker-update

Recompiled minified assets.

Conflicts:
	assets/default/css/style.css
	assets/default/js/scripts.min.js
Rename bootstrap-datepicker.css

Rename bootstrap-datepicker.css  to .scss so SASS includes the file in the compiled style.css.
Merge pull request #61 from Jadaw1n/datepicker-update

Datepicker update, solved #54