D21502: [PlasmaComponents3] Vertically center button text as well

[Nathaniel Graham]

ngraham marked 3 inline comments as done.

REPOSITORY
  R242 Plasma Framework (Library)

REVISION DETAIL
  https://phabricator.kde.org/D21502

To: ngraham, #plasma
Cc: broulik, apol, kde-frameworks-devel, michaelh, ngraham, bruns