Build: Update grunt and grunt-jscs-checker, use jquery preset for jscs
Datepicker: Fix Spanish locale data

Fixes #9735
Closes gh-1166
Merge branch 'master' of https://github.com/jquery/jquery-ui

# By Jörn Zaefferer (1) and Scott González (1)
# Via Scott González
* 'master' of https://github.com/jquery/jquery-ui:
  Datepicker: Fix Spanish locale data
  Build: Update grunt and grunt-jscs-checker, use jquery preset for jscs