added /seen Command

revised how the GU.Timestamp works so that different commands can have
different cooldowns.
Changed GU.Timestamp returns from strings to booleans.
Added a "/seen" command.
the /seen command will search for a User's ID# or a partial (or whole)
name. and return the day and time they were last seen. Also will tell
whether they were chatting leaving or simply joined the broadcast. ATM
15 sec cooldown.
Corrected and added some facts.