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/window-license-agreement.hpp

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <memory>
+#include "ui_OBSLicenseAgreement.h"
+
+class OBSLicenseAgreement : public QDialog {
+	Q_OBJECT
+
+private:
+	std::unique_ptr<Ui::OBSLicenseAgreement> ui;
+
+public:
+	OBSLicenseAgreement(QWidget *parent);
+};