D17905: [frameworks] Don't use light font styles for headings (1/3)

[Filip Fila]

filipf added a reviewer: Frameworks.

REPOSITORY
  R242 Plasma Framework (Library)

REVISION DETAIL
  https://phabricator.kde.org/D17905

To: filipf, ngraham, #plasma, #vdg, #frameworks
Cc: kde-frameworks-devel, michaelh, ngraham, bruns