2014-02-24  Thomas Quinot  <quinot@adacore.com>

	* g-stheme.adb, g-socthi-vms.adb, g-socthi-vms.ads,
	g-socthi-vxworks.adb, g-socthi-vxworks.ads, g-stseme.adb,
	g-socthi-mingw.adb, g-socthi-mingw.ads, g-socthi.adb,
	g-socthi.ads, g-socket.adb (Host_Error_Message): Return a string, not
	a chars_ptr, because on Windows this is a renaming of
	Socket_Error_Message.

From-SVN: r208082