For mouse wheel scrolling, search upward through the pane hierarchy for a viewport to scroll. This fixes mouse wheel scrolling in Clouseau.
For mouse wheel scrolling, search upward through the pane hierarchy for a
viewport to scroll. This fixes mouse wheel scrolling in Clouseau.

Assorted other minor changes.

informatimago/mcclim,quek/mcclim,informatimago/mcclim,quek/mcclim