Disabling failing microbenchmark tests.  When these tests fail, they halt test execution
preventing other test suites from executing
pointing default perf tests to localdb rather than sqlexpress
Adding a convention to discover navigation properties and the entity types to which they point.
Removing shadow props if the FK on them is removed.
Adding sugar to get associated navigations from foreign key.
Fixing some issues with self referencing relationships.

Fixes #1225