ST: Add WM_ICON_NAME property support

Also added _NET_WM_ICON_NAME.

win.h

@@ -30,6 +30,7 @@ void xdrawline(Line, int, int, int);
 void xfinishdraw(void);
 void xloadcols(void);
 int xsetcolorname(int, const char *);
+void xseticontitle(char *);
 void xsettitle(char *);
 int xsetcursor(int);
 void xsetmode(int, unsigned int);