Column names with '-' create invalid property names in generated code

Column names that contain a '-' create a generated class that can't be compiled. I'm using MySQL which allows such characters.

To fix, I changed the SqlManager class getColumnNames and getColumnTypes methods to replace the '-' with '_' on the colName string.

I'm sure there are other column characters that are illegal java identifiers, so perhaps a general escape mechanism should be applied.

- Ferdy