Fix keyword parsing

Some time ago, SmugMug move to using commas or semi-colons as a delimiter over spaces. And recently we removed support for space delimiting. This commit changes the keyword string from a quoted space delimited string into a comma delimited string.

eg. keyword1, keyword2, keyword3
Fix keyword parsing

@devbobo's fix for keyword parsing; SmugMug now uses commas instead of
spaces to separate keywords.

https://github.com/aarone/smugmugexport/pull/2
Updated version to 1.0.14