Table 3 and Figs. 7, 8, 16-20 are only available in electronic form at http://www.aanda.org

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Full Table 1 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/492/145

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Based in part on observations obtained with the Asiago telescopes.

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