* Adding mysql support
* Fixing other test cases
* Tests passing on mysql
* Fix the row number generation
* Adding blocks_history table
* merging the migrations in one single set of files
* Passing mysql tests
* Fixing default encoding on mysql
* Simplifying things
* Removing from the blocks table all deleted blocks
* Better indentation
* Moving db types to constants to make it less error prone
* reducing duplicated code
* Removing log line
* Now sql tests are running properly in mysql, sqlite and postgres
