D16954: Add find module for Google's libphonenumber

[Volker Krause]

vkrause added reviewers: Build System, Frameworks.

REPOSITORY
  R240 Extra CMake Modules

REVISION DETAIL
  https://phabricator.kde.org/D16954

To: vkrause, #build_system, #frameworks
Cc: kde-frameworks-devel, kde-buildsystem, michaelh, ngraham, bruns