QML UI: Implement saving of dives

This implements saving of some dive details to the cloud service. When the
user closes an open dives, any changed details will be cached, and when they
click on the 'Save Changes' button is pressed, the changes will be saved to
the cloud.

Signed-off-by: Grace Karanja <gracie.karanja89@gmail.com>

qt-mobile/main.qml

@@ -54,6 +54,14 @@ ApplicationWindow {
 								manager.loadDives();
 							}
 						}
+
+						Button {
+							id: saveChanges
+							text: "Save Changes"
+							onClicked: {
+								manager.saveChanges();
+							}
+						}
 					}
 
 				}