Revised JS vendoring Jan22

Removed, moved JS and coffee files, added necessary lines to application.js:

* delete mode 100644 app/assets/javascripts/bootstrap-modal.js
* delete mode 100644 app/assets/javascripts/omniauth_callbacks.js.coffee
* delete mode 100644 app/assets/javascripts/proposals.js.coffee
* delete mode 100644 app/assets/javascripts/votes.js.coffee
* rename {app => vendor}/assets/javascripts/bootstrap-alert.js
* rename {app => vendor}/assets/javascripts/bootstrap-button.js
* rename {app => vendor}/assets/javascripts/bootstrap-carousel.js
* rename {app => vendor}/assets/javascripts/bootstrap-collapse.js
* rename {app => vendor}/assets/javascripts/bootstrap-dropdown.js
* rename {app => vendor}/assets/javascripts/bootstrap-popover.js
* rename {app => vendor}/assets/javascripts/bootstrap-scrollspy.js
* rename {app => vendor}/assets/javascripts/bootstrap-tab.js
* rename {app => vendor}/assets/javascripts/bootstrap-tooltip.js
* rename {app => vendor}/assets/javascripts/bootstrap-transition.js
* rename {app => vendor}/assets/javascripts/bootstrap-typeahead.js