DNET-521
Added FbMigrationSqlGenerator.
Implemented RenameTableOperation.
Renaming procedure.
Renaming index.
Setting default FbMigrationSqlGenerator.
Some not supports.
Drop index.
Drop procedure.
Drop table.
Rename column.
Dropping PK.
Dropping column.
Dropping FK.
Support for generating HistoryOperation.
Support for adding PK.
Creating index.
Adding FK.
Create&Alter procedure.
Refactoring.