Decoupled classes from MainWindow to reference Context
and Athlete (and introduced a couple of new headers).
We no longer pass around a MainWindow pointer to children
but pass a context instead.
There are still a few pieces left in MainWindow that need
to move to a better place;
* Setting/clearing filter selection
* Working with Intervals
* Adding/Deleting Rides
* Save on Exit
As mentioned previously there are lots of other parts to
this refactor left to do;
* break MainWindow Gui elements into Toolbar and Views
* migrate from RideItem and Ridelist to ActivityCollection
and Activity classes that are not tied into gui elements.
* introduce Application Context and AthleteCollection
The sidebar elements all get a blue focus rectangle on
Mac OSX. This is a platform specific setting. This patch
removes the focus rectangle for sidebar components only.
The interval view now allows the user to drag and drop intervals
up and down in the list.
We could extend the drag and drop of intervals to support analysis
of segments/intervals from multiple rides in the future too.
Fixes#405.
