UI: Rename 'obs' dir to 'UI'

This is to prevent confusion both when prefixing commits and when
reading the directory structure for the first time.

UI/slider-absoluteset-style.hpp

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <QProxyStyle>
+
+class SliderAbsoluteSetStyle : public QProxyStyle
+{
+public:
+	SliderAbsoluteSetStyle(const QString& baseStyle);
+	SliderAbsoluteSetStyle(QStyle* baseStyle);
+	int styleHint(QStyle::StyleHint hint, const QStyleOption* option,
+		const QWidget* widget, QStyleHintReturn* returnData) const;
+};