Add Intersil HTTP Basic auth pass reset (originally #453)

[wchen-r7]

The modified version of pull request #453. This addresses a couple
of things including:

• Change the description to better explain what the vulnerability is.
  The advisory focuses the problem as an auth bypass, not DoS,
  although it can end up dosing the server.
• The title and filename are changed as a result of matching that
  advisory's description.
• Use 'TARGETURI' option instead of 'URI'.
• The reset attempt needs to check if the directory actually has
  401 in place, otherwise this may result a false-positive.
• The last HTTP request needs to check a possible nil return value.
• More verbose outputs.