Added ability to set global encoding when creating tables

Lately, we've had some problems with encoding in some of our tables. To our surprise, it was because of ruckusing using the servers default encoding to create the table. I've found out that you can add options every time you use the create_table method but human factor makes that an unreliable way of making the encoding.

So this pull-request adds the ability to add a 'charset' option to your configuration file and the charset will be used when creating all the tables, even without explicitly adding the option to the create_table method.