add option to ignore exceptions thrown executing formulas

[beninsydney]

I am modifying one worksheet of a spreadsheet and then recalculating the values. Some of the other sheets have some erroneous formulas and the recalculation aborts as soon as an exception is thrown.

To prevent this I have:

• wrapped formula execution in try/catch
• added options parameter to the method
• if the options parameter is not provided the exception throws per original behavior.
• if options.continue_after_error is specified the error is not thrown
• if options.log_error is specified some information is outputted with console.log