saslserv/main: Fix double free of pending sessions in _moddeinit()
saslserv: Register and unregister sasl mechs through the main module

Modules providing sasl mechs no longer come and go behind the back of saslserv/main
saslserv/main: Remove pending sessions on mech unregister
saslserv: Enable unload capability on all modules
saslserv/main: Log when the session list is non-empty on unload
saslserv/{dh-aes,dh-blowfish}: Fix unsigned compare to immediate -1 leading to DH_compute_key() return check being possibly optimized away
Mark InspIRCd 1.2 support as deprecated in the config and doc/IRCD

(cherry picked from commit e1efd13bee846a6201b31e9ebb71ae68232b6126)
protocol/inspircd: Clean up whitespace
protocol/inspircd: Remove support for InspIRCd 2.1 beta
protocol/inspircd: Bump minimum required protocol version to 1202 (2.0)
protocol/inspircd: Parse CAPAB USERMODES
protocol/inspircd: Expect AWAY with a TS
protocol/inspircd: Add handler for SAVE
protocol/inspircd: Add handler for FIDENT
protocol/inspircd: Negotiate protocol version 1202 (2.0)
protocol/inspircd: Remove SVSNICK handler

InspIRCd 2.0 and above does not send SVSNICK by itself anymore; we only receive it when a pseudoserver sends it, which is safe to ignore
protocol/inspircd: Only allow NICK messages from users
protocol/inspircd: Require a TS in NICK messages
protocol/inspircd: Don't treat the first param as a comma separated list in m_part()

InspIRCd generates one PART message for each parted channel
protocol/inspircd: Use our sid as the source when sending VERSION