Comment 16 for bug 171007

Looks good on Ubuntu 10.04.

Some UI/cosmetic comments:
1. The option group has no label.
2. The comment in the List tab should end with a period.
3. The python strings are not translatable.

Attached is a proposal for these minor issues (I used an enum list because minimal option groups have an alignment problem).

A remaining small bug: the message dialog return an error when "Find this font" is empty:
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Traceback (most recent call last):
  File "replace_font.py", line 253, in <module>
    e.affect()
  File "/usr/local/share/inkscape/extensions/inkex.py", line 216, in affect
    self.effect()
  File "replace_font.py", line 241, in effect
    find = self.options.fr_find.strip().lower()
AttributeError: 'NoneType' object has no attribute 'strip'
---