added package.json
fixed bug
fixed bugs
modified package.json
added use strict, fixed bugs
fixed bugs, modified function and variable names, modified controlling access to functions and variables
modified colname
release v0.2.0, modified api, fixed bugs
release v0.2.1, fixed bug, added workbook.cleanUp()
fixed bugs
modified Readme.md, release v0.2.2
modified Readme.md