Log Message:
Update py-xlrd to 0.7.7.

0.7.7.
This release features the following changes:
- Google Spreadsheet doesn't write the undefined-contents byte at the
  end of a NOTE record. Excel doesn't care. Now xlrd doesn't care either.
- Version information is now stored in a .py file, hopefully keeping
  py2exe and other freeze tools happy.

(0.7.5, 0.7.6 ...fixes packaging issues in 0.7.4...)

0.7.4.
This release features the following changes:
- Fixed a bug where xlrd was silently truncating long text formula results
- Avoid parsing STYLE records when formatting_info=False
- More tolerance of out-of-spec files.
- Minor performance improvements.