`bower install --save Polymer/core-elements`
Added component files for "Polymer/core-elements"
`bower install --save Polymer/polymer-elements Polymer/polymer-ui-elements`
All added component files for polymer-elements and polymer-ui-elements
polymer/.bower.json: `bower update` removed 'direct = true' line
`bower install --save Polymer/polymer-ajax` -> bower.json change only
(polymer-ajax was already installed for dependency)
polymer-ajax example.