Removed relational model and replaced with metadata model where needed.
Updated related code and tests.
Added tests to validate that issues #1077 and #1078 are fixed.
1077: Migrations: identity: false not respected when creating tables.
1078: Migrations: nullable: false not respected when creating tables.
Moved Column from Relational.Model to Migrations.Model
Moved RelationalMetadataExtensionProvider to test code. Implemented SQLiteMetadataExtensionProvider to return Relational extensions.
Added RelationalTestHelper and MigrationsTestHelper.
React to GetDefaultServices changes
Merge branch 'dev' of https://github.com/aspnet/EntityFramework into dev
Updating the format of perf results