Introducing MySQL Reconnect.
When MySQL disconnects during runtime, the server tries to reconnect either indefinitely (default) or a specified number of times before shutting down.
(Merged from Hercules a4a549d, 64d34dc)

git-svn-id: https://rathena.svn.sourceforge.net/svnroot/rathena/trunk@17120 54d463be-8e91-2dee-dedb-b68131a5f0ec