Refactor MainWindow Part 2 of 5

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

src/DataProcessor.cpp

@@ -17,7 +17,7 @@
  */
 
 #include "DataProcessor.h"
-#include "MainWindow.h"
+#include "Context.h"
 #include "AllPlot.h"
 #include "Settings.h"
 #include "Units.h"
@@ -56,7 +56,7 @@ DataProcessorFactory::autoProcess(RideFile *ride)
     return changed;
 }
 
-ManualDataProcessorDialog::ManualDataProcessorDialog(MainWindow *main, QString name, RideItem *ride) : main(main), ride(ride)
+ManualDataProcessorDialog::ManualDataProcessorDialog(Context *context, QString name, RideItem *ride) : context(context), ride(ride)
 {
     setAttribute(Qt::WA_DeleteOnClose);
     setWindowTitle(name);