Added epeen, privmsg plugins. Modified sieve.

Sieve Plugin - Too many folks with the word "bot" at the end of their
names prompted me to remove the bot ignore completely.

Epeen Plugin - Ironic IRC Karma plugin. Stroke e-peens and gather glory.

Privmsg Plugin - Modifies core msg() functionality to accept a 'special'
parameter to privmsg a specific person, channel, or entity.

Say Plugin - Removed unnecessary regex import.

Down Plugin - Just edited some return strings.