Update for select2
Merge branch 'master' of git://github.com/ivaynberg/select2

* 'master' of git://github.com/ivaynberg/select2: (102 commits)
  fix select2 csp errors / warnings
  Update select2.css
  Unit of measure px is redundant
  Update and improve Persian (fa) translations
  Bugfix - only selected options that are not disabled should be used when initializing the dropdown
  Update select2_locale_hu.js
  update copyright year
  Allow chaining for .select2('readonly', ...)
  Accept strings as well as functions for localization
  Allow to display item created by createSearchChoice at the end of the list ref #595
  The function hideSelectionFromResult was tested against undefined as a property and not as a function
  merge
  Use dppx instead of non-existing ppx resolution unit
  Fix for #2042 Chrome bug: Reset the background position for multiple backgrounds
  Optional Search Input Placeholder parameter added
  Add hideSelectionFromResult function
  Accessibility updates based on jQuery UI Autocomplete
  singleSelect: setting nextSearchTerm in initSelection
  Changed default text for min number of characters.
  Update package.json on release
  ...