Add missing sorttable.js library

* Add sorttable.js library missing from previous commit.
Fix variable name in profile set up

* Fix variable name in profile set up that would cause a server error if
profile set up fails.
* Add handlers for Playlist pages.
Fix alert colour in location page

* Change location page alert colour from 'danger' to 'info', as the
alert is meant to inform the user that s/he has no locations.
Add missing link to add location page in location page
Standardise button colours in add location page

* Use 'info' for 'helper' actions.
* Use 'success' for 'affirmative' actions.