auth: NULL pointer check
Merge branch 'master' of github.com:atheme/tethys
msg: Count total usecs and number of command invocations.
By-ref lookups require connection for context now

This is to prevent users from using refs like UIDs in commands (i.e.,
/WHOIS, /KICK, etc.)
Get rid of redundant entity system
sendto: Make u_sendto_{start,skip} public
Add preliminary ENCAP support
Add ENCAP SU
Move user mode processing system to u_modes (closes #10)
Allow remote users to set any user modes they want
core/euid: Process user mode parameter
Put user modes in EUID
core/join: Preliminary SJOIN mode processing
Add +S user mode (network service)
core/whois: Talk about +S
core/whois: Talk about the account in use
core/mode: Use u_user_by_ref vs _by_nick
core/whois: Suppress channel list on users with +S
Add TB
Fix bugs with SJOIN and TB