Make sidebar topic expand on click and fix html formatting of elided text. (#96)

Fixes #95

include/ui/Label.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <QLabel>
+
+class Label : public QLabel
+{
+        Q_OBJECT
+
+public:
+        explicit Label(QWidget *parent = Q_NULLPTR, Qt::WindowFlags f = Qt::WindowFlags());
+        explicit Label(const QString &text,
+                       QWidget *parent   = Q_NULLPTR,
+                       Qt::WindowFlags f = Qt::WindowFlags());
+        ~Label() override {}
+
+signals:
+        void clicked(QMouseEvent *e);
+        void pressed(QMouseEvent *e);
+        void released(QMouseEvent *e);
+
+protected:
+        void mousePressEvent(QMouseEvent *e) override;
+        void mouseReleaseEvent(QMouseEvent *e) override;
+
+        QPoint pressPosition_;
+};