Filter: move recalculation of filter from FilterModel to TripModel

The way this was accessed via Qt's model semantics was horrible.
This gives arguably more readable code, since we don't have to
shoehorn things through QVariants.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

qt-models/filtermodels.h

@@ -4,31 +4,18 @@
 
 #include "divetripmodel.h"
 
-#include <QStringListModel>
 #include <QSortFilterProxyModel>
-#include <QDateTime>
-
-#include <stdint.h>
-#include <vector>
 
 class MultiFilterSortModel : public QSortFilterProxyModel {
 	Q_OBJECT
 public:
 	static MultiFilterSortModel *instance();
 	bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const override;
-	bool updateDive(struct dive *d); // returns true if visibility status changed
 	bool lessThan(const QModelIndex &, const QModelIndex &) const override;
 
 	void resetModel(DiveTripModelBase::Layout layout);
-	void myInvalidate();
-
-signals:
-	void filterFinished();
-
 private:
 	MultiFilterSortModel(QObject *parent = 0);
-	// Dive site filtering has priority over other filters
-	void countsChanged();
 };
 
 #endif