(update to the new pikotools api): use a char32_t character as a main character when converting strings

Use a char32_t instead of a wchar_t type. This is needed on systems
where sizeof(wchar_t) is equal to 2.

This affects classes based on the pt::Stream such as Log and HtmlTextStream.

winixd/core/log.h

@@ -74,6 +74,7 @@ public:
 	virtual Log & operator<<(char s);
 	virtual Log & operator<<(unsigned char);
 	virtual Log & operator<<(wchar_t s);
+	virtual Log & operator<<(char32_t s);
 	virtual Log & operator<<(bool);
 	virtual Log & operator<<(short);
 	virtual Log & operator<<(int s);