Mexico 1965 graphic updates

Last update 19/09/04: addons by Legends of '65 v1.0 and sky form Al Heeley !

Track is updated with addons by Legends of '67 and sky/horyzon by Alan Heeley.
1-copy files from Lo65 Mexico patch v1.0 , downloadable from Legends of '65.
2-copy files from alskies_mexico_v1.0.zip, downloadable from HERE.