Fixed Byte[] issue

With this commit the issue regarding byte arrays is fixed (issues #107 and #109). I added tests for the following dialects: SQL Server, SQLite, MySql, PostgreSQL and Firefird

By default (see OrmLiteDialectProviderBase methods GetQuotedValue and ConvertDBValue) fields with the type byte[] are converted to base64 when stored and converted back from base64 when read (using the TypeSerializer). The last step was missing and so the value read was not equal to the original value.

In the existing implementation of the SQL Server dialect, this behavior was already overwritten (the original byte array is store, no conversion is needed). I realized the same behavior for the MySql dialect.