* Add support for XLSM files from PR 101 (thanks caffeinatedMike)
0.9.0
* Fix unintentional trimming of whitespace on strings * Filter invalid XML characters to prevent corrupted Excel files from being saved
0.8.0
* Add ability to enable auto filters * Add ability to write to file handle
0.7.3
* Performance optimizations * Fix invalid function/formula references in third-party spreadsheet software * Remove Python 2.6 support from test suite; Python 2.6 will no longer be supported in future 0.8.0 release
0.7.2
* Strip tzinfo from datetime objects (issue 59) * Minor bug fixes and performance improvements * Remove support for Python 3.2 * Add support for Python 3.6