Merge pull request #3438 from ussuri/new-utility-functions

Added _getFile and _isSingleFileMatchingRegex
Merge pull request #3470 from ussuri/small-fixes-3

Fix wrong return type
Merge pull request #3473 from ussuri/polymer-designer-code-as-is

Polymer Designer code "as is"
Merge pull request #3474 from ussuri/cde-polymer-designer

CDE Polymer Designer implementation