Problem with fuzzy comparison where the Abstract is "Not Available"

[hollandjg]

When importing these two papers:
http://adsabs.harvard.edu//abs/1916AnP...354..769E
http://adsabs.harvard.edu/abs/1917SPAW.......142E
the second replaces the first.

The abstract in each case is "Not Available" but the titles are very different.

[RuiPereira]

Actually the titles are not very different, the standard cutoff of 0.7 needs to be raised to 0.76 to be able to separate both:

In [9]: difflib.get_close_matches(u'Die Grundlage der allgemeinen Relativitätstheorie', [u'Kosmologische Betrachtungen zur allgemeinen Relativitätstheorie'], n=1, cutoff=.7)
Out[9]: [u'Kosmologische Betrachtungen zur allgemeinen Relativit\xe4tstheorie']

In [10]: difflib.get_close_matches(u'Die Grundlage der allgemeinen Relativitätstheorie', [u'Kosmologische Betrachtungen zur allgemeinen Relativitätstheorie'], n=1, cutoff=.76)
Out[10]: []

As mentionned in the code, the cutoff parameter could be moved to the preferences to prevent this type of corner cases, but for a quick fix you could just change line 311 of your adsbibdesk.py copy.