Correct wordpress_login_enum for #2301

tabassassin created a mess and I failed to resolve it properly.
Attempt #2. See #2301.
FixRM #8396 change all lib use of regex to 8-bit pattern
Fix description
Update information about original discovery

Update info about original discovoery. See #2337 too.
Land #2363, updated info about the Hitcon bug
Land #2362, update description
Land #2357
Land #2360

All the specs pass, and it's difficult to repo many of these cases to
see if bugs are actually here, but it's a good idea to enforce binary
regexs.
Merge remote-tracking branch 'upstream/master'