create scenario with two composite straight leg forecasts
introduce method to set the color-coding for a particular contribution
allow Straight Leg contributions to have their own color
allow these two views to listen out for color changes in the child contribution
improve comments
Issue #650 - fixing background on Linux
insert comment explaining special case
Merge pull request #652 from debrief/issue650

 fixes PR #651 fixes issue #650
Issue #647 - Color coded Straight Leg forecast Contributions
Fix for when time sliders don't cover start of track period
Merge pull request #655 from debrief/hotfix/ian/slider_start_time

Fix for when time sliders don't cover start of track period
Merge pull request #654 from pecko/issue647

Issue #647 - Color coded Straight Leg forecast Contributions

Incorporate Peco's rounded rectangles into development branch
modify to include color border, minor refactoring
listen out for the bounds being constrained - this is when we have new leg colors to display
refactor - include custom painting in top level, to prevent duplicating it in multiple children
introduce marker interface for contributions that have their own color
refactor, to move COLOR property name to parent class
remove per-contribution color change processing, just do it when the bounds have been constrainted. This also overcomes a problem where if a contribution is inActive we shouldn't give it a color, but since we don't get a property change, we never know about it.
minor refactoring, introduce debug lines
remove debug line