Add tooltips/legend for availability bar & progress bar

src/gui/properties/downloadedpiecesbar.cpp

@@ -33,6 +33,8 @@
 
 DownloadedPiecesBar::DownloadedPiecesBar(QWidget *parent): QWidget(parent)
 {
+  setToolTip(QString("%1\n%2\n%3").arg(tr("White: Missing pieces")).arg(tr("Green: Partial pieces")).arg(tr("Blue: Completed pieces")));
+
   m_bgColor = 0xffffff;
   m_borderColor = palette().color(QPalette::Dark).rgb();
   m_pieceColor = 0x0000ff;

src/gui/properties/pieceavailabilitybar.cpp

@@ -36,6 +36,8 @@
 PieceAvailabilityBar::PieceAvailabilityBar(QWidget *parent)
     : QWidget(parent)
 {
+    setToolTip(QString("%1\n%2").arg(tr("White: Unavailable pieces")).arg(tr("Blue: Available pieces")));
+
     m_bgColor = 0xffffff;
     m_borderColor = palette().color(QPalette::Dark).rgb();
     m_pieceColor = 0x0000ff;