changes here and there

exception.h

@@ -4,12 +4,16 @@
 
 #include <string>
 
-class Exception : public std::exception {
-private:
-	std::string	cause;
+namespace usql {
 
-public:
+    class Exception : public std::exception {
+    private:
+	std::string cause;
+
+    public:
 	Exception(const std::string &msg);
 
-	const char* what() const noexcept;
-};
+	const char *what() const noexcept;
+    };
+
+}