Automatically reconnect to the MySQL server if the connection has been lost,
independent from MySQLdb reconnect option which may not always be available.
This fixes Trac ticket #91.


git-svn-id: https://humgenprojects.lumc.nl/svn/mutalyzer/trunk@529 eb6bd6ab-9ccd-42b9-aceb-e2899b4a52f1