Further adjustments to the instrument controls

Changes to the grid layout: tighter layout margins, less horizontal
spacing to make the widget grouping more obvious, no more vertical
spacing to move the labels even more close to the widgets, widgets align
vertically on the center so that the spin boxes are centered with the
knobs.

Added a "STORE" label for the preset button to make the layout more
balanced.

src/tracks/InstrumentTrack.cpp

@@ -1308,12 +1308,13 @@ InstrumentTrackWindow::InstrumentTrackWindow( InstrumentTrackView * _itv ) :
 
 
 	QGridLayout* basicControlsLayout = new QGridLayout;
-	basicControlsLayout->setHorizontalSpacing(9);
-	basicControlsLayout->setVerticalSpacing(1);
+	basicControlsLayout->setHorizontalSpacing(3);
+	basicControlsLayout->setVerticalSpacing(0);
+	basicControlsLayout->setContentsMargins(0, 0, 0, 0);
 
 	QString labelStyleSheet = "font-size: 6pt;";
 	Qt::Alignment labelAlignment = Qt::AlignHCenter | Qt::AlignTop;
-	Qt::Alignment widgetAlignment = Qt::AlignHCenter | Qt::AlignBottom;
+	Qt::Alignment widgetAlignment = Qt::AlignHCenter | Qt::AlignCenter;
 
 	// set up volume knob
 	m_volumeKnob = new Knob( knobBright_26, NULL, tr( "Instrument volume" ) );
@@ -1397,6 +1398,11 @@ InstrumentTrackWindow::InstrumentTrackWindow( InstrumentTrackView * _itv ) :
 
 	basicControlsLayout->addWidget( saveSettingsBtn, 0, 7 );
 
+	label = new QLabel( tr( "STORE" ), this );
+	label->setStyleSheet( labelStyleSheet );
+	basicControlsLayout->addWidget( label, 1, 7);
+	basicControlsLayout->setAlignment( label, labelAlignment );
+
 	generalSettingsLayout->addLayout( basicControlsLayout );