Disables zooming by double click and context menu on marble.

Marble is a weird piece of Qt software, it seems that it wasn't
thought of being a library when first written. Most of its features
are not achieved by subclassing && overriding one of Qt default methods,
instead we need to eventFilter for almost everything ( which is a pain,
and a bit error prone - see our combo box delegate *puke*. )

This one's ready,  only one thing though - if we want to implement
our own context menu, we will need to use the eventFilter, and not
the contextMenuEvent.

Fixes #291

[Dirk Hohndel: this does not disable the context menu for me...]

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

qt-ui/globe.h

@@ -20,11 +20,10 @@ public:
 	void repopulateLabels();
 	void centerOn(struct dive* dive);
 	void diveEditMode();
-
+	bool eventFilter(QObject*, QEvent*);
 protected:
 	/* reimp */ void resizeEvent(QResizeEvent *event);
 	/* reimp */ void mousePressEvent(QMouseEvent* event);
-
 private:
 	void prepareForGetDiveCoordinates(struct dive* dive);
 	GeoDataDocument *loadedDives;