Change logger minlevel to "error" by default

[apophis79]

I humbly request that the FlexDMD.log.config file be updated such that the default rules have minlevel set to "error". For the common user, this will tend to minimize disk access during gameplay and provide a better performance experience.

<rules>
    <logger name="*" minlevel="error" writeTo="console" />
    <logger name="*" minlevel="error" writeTo="file" />
  </rules>