Timer changes and TimerManager enhancements

Timer::Tick() now has a bool return value: if false is returned the timer is deleted using operator delete, otherwise, if it's a repeating timer then it's rescheduled (readded)
Timers are removed from the TimerManager automatically at destruction

Timers are now stored in a multimap instead of a sorted vector
m_spanningtree Move CacheTimer into utils
Modularize DNS

The DNS modules are temporarily in commands/ so they're loaded automatically

Thanks to Attila for helping with much of this.
Fix Windows
Move <performance:nouserdns> to <connect:nouserdns>.