Refactoring SqlGenerator and using OUTPUT clause for Sql Server
Code cleanup
Added MigrationTool class that implements the tool functionality. Code is using the existing Configuration implementation.
Added Program class that handles command line arguments and loading the config file. This is also needed by the K command framework.
Modified Migrator and MigrationScaffolder where needed.
Added unit tests.

TODOs: Add more logging, support --SourceMigration option, more testing.

See tool usage in resx for details
Adding full support for optimistic concurrency in the update pipeline
Fixes #399: Cannot update identity column with int primary key
Update nupkg patching logic
Migrations: Add PowerShell commands