Support for markdown prefixes and comment blocks
Hashtag header prefixes of 1-6 hashes causes problems with our current normalizer which only takes the first
hash and can cause mismatches between input license and template matching. Instead of only taking the first #
as a typical line comment, we can now take up to ###### as a comment/markdown prefix consistently.
** In addition the copyleft-next and perhaps others use blocks like this. **
The same regex handles these asterisks, but currently only takes 1. Now it also will take 1-6.
So whether it is markdown or a comment prefix/suffix, this modification allows the normalizer to remove 1-6
leading hashtags and 1-6 leading or trailing asterisks.