Added simpler import. Closes #26
Fix for non optional write_datetime() format. Closes #33
Fix for NAN/INF converted to invalid numbers in write(). Closes #30
Fixed docs for write() args. Closes #31
Added constructor option to preserve numbers in strings in write(): Issue #34
Added contribution guidelines.
Added constructor option for adding default date format. Issue #5
Prep for release 0.3.6
Added handling for Python and Excel boolean values. Issue #37
Changed strings_to_numbers default to False.
Remove stuff that is not python 2.5 compatible (uncomment)
added unicode prefix to literal
added missing parameter
Updated docs to reflect strings_to_numbers change.
Added tox config file for testing.
Added PYPY test target.
Merge branch 'strict_type'
Prep for release 0.3.7
Restore 3.x compatibility by using binary prefix
Moved python-2.5-incompatible prefixes into evals