Update home directory install to use XDG based directory constant (synonym).

indra/newview/linux_tools/install.sh

@@ -58,7 +58,7 @@ function homedir_install()
 	exit 0
     fi
 
-    install_to_prefix "$HOME/.local/share/alchemy-install"
+    install_to_prefix "$XDG_DATA_HOME/alchemy-install" #$XDG_DATA_HOME is a synonym for $HOME/.local/share/ unless the user has specified otherwise (unlikely).
 }
 
 function root_install()