Stellar and planet parameters updated (HD 209458)

Age: http://www.aanda.org/articles/aa/pdf/2006/46/aa5954-06.pdf
Temperature: http://arxiv.org/pdf/1103.0757v1.pdf
Update HD 209458.xml
Merge pull request #191 from jaroslavmerc/patch-40

Stellar and planet parameters updated (HD 209458)