The project pane rewrite version 2.

This splits up the edit and active settings. Let people try it and
report usability problems. I'm not 100% convinced of the layout either.

src/libs/utils/detailsbutton.cpp

@@ -0,0 +1,21 @@
+#include "detailsbutton.h"
+
+using namespace Utils;
+
+DetailsButton::DetailsButton(QWidget *parent)
+#ifdef Q_OS_MAC
+    : QPushButton(parent)
+#else
+    : QToolButton(parent)
+#endif
+{
+#ifdef Q_OS_MAC
+    setAttribute(Qt::WA_MacSmallSize);
+    setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
+    s.upButton->setIconSize(QSize(10, 10));
+    s.downButton->setIconSize(QSize(10, 10));
+#else
+    setCheckable(true);
+#endif
+    setText(tr("Details"));
+}