Change the "md5" key to an array of sections [md5:<sum>]

... instead of a comma-separated list. .ini lines are limited in length,
MD5sums are kind of long and would limit the number of .exe versions we
could support. Also, no we now have a way to correlate and report version
numbers/strings and URLs with each exe version. The "ver" and "url" keys
are not yet displayed or used for anything and are thus optional.