We use a custom build of jquery to reduce size.

$ git clone git://github.com/jquery/jquery.git
$ cd jquery
$ git checkout 2.1.1
$ npm install
$ grunt custom:-ajax,-ajax/script,-ajax/jsonp,-ajax/load,-ajax/parseJSON,-ajax/parseXML,-ajax/script,-ajax/var/nonce,-ajax/var/rquery,-ajax/xhr,-manipulation/_evalUrl,-deprecated,-effects,-effects/Tween,-effects/animatedSelector,-event-alias,-offset

Make sure that you update all three generated files. Minified,
non minified and the map.