Replaced vsnprintf with VAFORMAT in users.cpp
Replaced vsnprintf with VAFORMAT in channels.cpp
Updated SendWhoisLine in helperfucks.cpp to use VAFORMAT instead of vsnprintf
Replaced vsnprintf in snomask.cpp with VAFORMAT
Replaced vsnprintf in logger.cpp with VAFORMAT
Replaced vsnprintf with VAFORMAT in usermanager.cpp
Replaced vsnprintf with VAFORMAT in m_spannintree/main.cpp