Add depth colum to cylinder model

To make the planner work this adds a new column to the Cylinder widget
(depth - for the depth at which we want to change to a certain gas
during deco).

This also tries to hide that column in the equipment view and hide the
start/end pressure columns in the planner view. Oddly that fails :-(

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

qt-ui/tableview.cpp

@@ -7,7 +7,7 @@
 #include <QTextStream>
 #include <QSettings>
 
-TableView::TableView(QWidget *parent) : QWidget(parent)
+TableView::TableView(QWidget *parent) : QTableView(parent)
 {
 	ui.setupUi(this);
 	QFile cssFile(":table-css");