Support deleting folder content or cancel convert
Support deleting folder content or cancel convert

Why:

 * Currently when generating we just add files to folder causing
   duplicates. Better if we could keep the folder clean or overwrite files
   instead of creating duplicates.

This change addreses the need by:

 * Offer to delete the folder if already found or cancel if you do not want
   to delete.

maxandersen/gdoc2adoc