add ChatForm:ClearFace()

Not added to ChatForm:Clear(), because scripts typically want to set the
face once for the entire Player/NPC dialogue, but clear the other chat form
contents for each dialogue node.
clear face when switching to candidate crew list. fixes #2647
modelviewer: display the ship's bounding box with the collision mesh
Merge remote-tracking branch 'johnbartholomew/modelviewer-show-aabb'
Merge remote-tracking branch 'johnbartholomew/issue-2647'
ocd fix
auto-commit: translation updates