m_sajoin, m_sapart Support a comma separated list of channels

Issue #818
core_lusers Don't capitalize "local users" and "global users"
Remove WALLCHOPS and WALLVOICES ISUPPORT tokens

These tokens have been deprecated in favour of STATUSMSG for a long time
m_spanningtree Throw an exception on protocol violations instead of returning CMD_INVALID

Catch CoreExceptions, log and close the link in OnDataReady()
m_spanningtree Add ServerCommand::ExtractTS() to convert string to raw TS

Throws a ProtocolException if the input is invalid