Make thumbs up robust for empty / small catalogs

[taldcroft]

Closes #185.

Also bumps version to the next (maybe last?) feature release.

[jeanconn]

I think this is fine. I wasn't sure if we wanted to add the p_acq column to the empty AcqTable (with similar changes for empty fid or guide tables) or handle with logic like this for the three kinds of tables.

[jeanconn]

Ok. With this change I can cut this on the matlab side

try
    pcat.Acq.thumbs_up = pyexec('tu = int(catalog.acqs.thumbs_up)', 'tu');
    pcat.Guide.thumbs_up = pyexec('tu = int(catalog.guides.thumbs_up)', 'tu');
    pcat.Fid.thumbs_up = pyexec('tu = int(catalog.fids.thumbs_up)', 'tu');
    pcat.thumbs_up = pyexec('tu = int(catalog.thumbs_up)', 'tu');
catch exception
    warning(exception.message)
    pcat.thumbs_up = 0;
    pcat.Fid.thumbs_up = 0;
    pcat.Guide.thumbs_up = 0;
    pcat.Acq.thumbs_up = 0;
end