version 0.20 (2012-Aug-7)

version 0.19 (2012-May-17):
  * issue #12 fix, some kind of unknown excel app version

version 0.18 (2012-Feb-19):
  * Support for multi-region shared-strings (merge #11)

version 0.17 (2012-Feb-14):
  * issue #10 fix

version 0.16 (2011-Oct-26):
  * new date format

version 0.15 (2011-Sep-16):
  * datetime 1904 format support
  * datetime format bug fix

version 0.14 (2011-jul-15):
  * recursively convert the xlsx files in a directory to csv (Zhehao Mao's patch)

version 0.131 (2011-apr-19):
  * skip empty lines option

version 0.13 (2011-jan-16):
  * sheet no bug fix

version 0.12 (2010-dec-21):
  * fix last column empty bug

version 0.11 (2010-sep-13):
  * no numFmt bugfix

version 0.1 (2010-sep-12):
  * better support for date/time formats
  * two letter columns bug fixed
  * sheets support added
  * unicode fix
  * boolean type
  - thanks to Neil Killeen

version 0.0 (2010-jun-11):
  * xlsx to csv convertor first release
