Win32: Rewrite the service wrapper

Edited original commit to pass MAX_PATH as nSize to GetModuleFileNameA() instead of 101 after approval from author @ChrisTX (Attila Molnar)

Fixes #404 reported by @crchauffe
Accept -c as a command line argument (equivalent to --config)
m_xline_db Major enhancements

- Save database on a timer, not on every single change
- Use the internal database instead of keeping track of xlines ourselves
m_xline_db Fix pointless excessive stack usage in ReadDatabase()
Added support for EXTERNAL
Merge pull request #443 from ShutterQuick/sasl_external

Added support for SASL EXTERNAL
cmd_lusers Fix miscounting
Fix premature overwriting of OLDTIME that resulted in time drifts never being detected