Make two UI modifications in Welcoming window and Help-About dialog.#2752

Merged

pmuetschard merged 7 commits intogoogle:masterfrom stellama0208:ui_checkin

Jun 10, 2019

+135-15

Commits on Jun 3, 2019

Change to different shorcut hint for macOS.
stellama0208
committed

Commits on Jun 4, 2019

Further modifications based on comments.
stellama0208
committed

Commits on Jun 7, 2019

Make code style enhancement.
stellama0208
committed