Reorganizing source code. Created util dir

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/util/warning.h

@@ -0,0 +1,64 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    warning.h
+
+Abstract:
+
+    Support for warning messages.
+
+Author:
+
+    Leonardo de Moura (leonardo) 2006-12-01.
+
+Revision History:
+
+--*/
+#ifndef _WARNING_H_
+#define _WARNING_H_
+#include<iostream>
+#include<stdarg.h>
+
+class ini_params;
+
+void send_warnings_to_stdout(bool flag);
+
+void enable_warning_messages(bool flag);
+
+void set_error_stream(std::ostream* strm);
+
+void set_warning_stream(std::ostream* strm);
+
+void warning_msg(const char * msg, ...);
+
+void register_warning(ini_params & p);
+
+void disable_error_msg_prefix();
+
+void format2ostream(std::ostream& out, char const* fmt, va_list args);
+
+class warning_displayer {
+    const char * m_msg;
+    bool         m_displayed;
+public:
+    warning_displayer(const char * msg):
+        m_msg(msg),
+        m_displayed(false) {
+    }
+
+    void sign() {
+        if (!m_displayed) {
+            warning_msg(m_msg);
+            m_displayed = true;
+        }
+    }
+
+    void reset() {
+        m_displayed = false;
+    }
+};
+
+#endif /* _WARNING_H_ */
+