test-config is now a config inside Test-kit and not a separate project.
CodeGeneratorMain and associated 'code-generate' sbt task added.
sbt changes to have CodeGeneratorTest, some fixes for CodeGenerator.

Conflicts:
	slick-testkit/src/test/scala/scala/slick/test/jdbc/CodeGeneratorTest.scala
Merge branch 'topic/type-provider-code-gen' into wip/YY7