Fix handling of dropupAuto.

Previously, any dropup setting was lost after first click.
Add composer.json
Fix trailing comma in composer.json
Update composer.json
Update README.md
Update README.md
Update CONTRIBUTING.md
Fix #408
Fix #408
Fix #391
Fix #391
Fix #386
Fix #386
Fix #409
Fix #409
Close #369
Update bootstrap-select.min.js