Purge the old chanlog code from the module file.
Merge pull request #541 from SaberUK/master+chanlog

Purge the old chanlog code from the module file.
Start to replace MAXBUF with <limits:maxline>.
Reserve ServerLimits::MaxLine instead of MAXBUF.
Compare to ServerLimits::MaxLine instead of MAXBUF.
Use iostream instead of C-style file operations.
Use InspIRCd::Format instead of snprintf().
Replace some C string operations with the + operator.