m_spanningtree IDLE handler: Rewrite
m_spanningtree FMODE handler: Rework

Check for error conditions before doing any work
Get rid of hardcoded maxmodes and a loop that copies a container
m_spanningtree UID handler: Remove dead code
m_spanningtree UID handler: Log and drop the link when a server introduces a user with an unknown user mode
m_spanningtree Netburst: Remove expiration check from SendXLines()

XLineManager does the checking
m_spanningtree Netburst: Rework SendFJoins()

Old code sent empty lines on burst after FJOINs, new version fixes that
m_spanningtree RCONNECT handler: Fix error reporting to remote users

Describe behavior in comments
m_spanningtree RSQUIT handler: Don't reimplement sending messages to remote users

Use ModuleSpanningTree::RemoteMessage instead
m_spanningtree atoi() to ConvToInt() conversion, add const where possible

Remove two redundant functions from Utils
m_spanningtree FTOPIC handler: Return CMD_FAILURE/CMD_INVALID as appropiate

Return CMD_FAILURE to prevent propagation when the topic wasn't updated; return CMD_INVALID when the topicts is invalid
m_spanningtree FTOPIC handler: Keep only one topic if the two topic timestamps match but the topics differ
m_spanningtree Utils: Move code that creates a full line from its components to a new function
m_spanningtree Change TreeServerList to be a set, get rid of a function dedicated to adding entries to it
m_spanningtree Introduce new function to send channel messages

Use it from the protocol interface and PRIVMSG/NOTICE handlers
Unite OnUserNotice and OnUserMessage code into LocalMessage()
m_spanningtree Remove encapsulation on UserCount/OperCount
m_spanningtree Change both prefix and first parameter of SQUIT to be a SID
m_spanningtree Netburst: Refactor SendChannelModes()

Rename it to SyncChannel() and change it to take a Channel* parameter, move iteration into DoBurst()
m_spanningtree FJOIN handler: Refactor, update doc

Split the core function into several smaller functions
Accept userlist entries having no comma at all
m_spanningtree Remove unneeded #includes