ADDREGEXPNEG <regexp_id> <nregexp>
[ADMIN] Adds regular expression negation to existing regular expression
  <regexp_id>: ID of existing regular expression to add negation to
  <nregexp>  : The regular expression negation pattern to add

If a connecting user matches a regular expression, their information
is then also compared against the list of negations for that 
expression.  If they match any of the expressions in the negation list
then they will not be klined.
