Do numeric comparison on db versions

Support MariaDB version 10.0 and forward, which previously did not appear to
be 'greater than' version 4.4 as in php '10.0' < '4.4'. Performing a split
by the dots allows php to perform a numeric comparison.
Merge pull request #630 from greezybacon/issue/629

Do numeric comparison on db versions

Reviewed-By: Peter Rotich <peter@osticket.com>