Stroll of the navigator... (Consolidate and better cache navigation access code)

Dependent navigations may be for collections or references. This code moves the check for collection/reference inside the cache lookup to avoid doing it over and over. Also, the property setter/getter are made available for collection nav props because these are needed for creating an setting a new collection automatically.
Fix #293
More work on relational filtering.
Adds more async extension methods

Fix #256
Update tests to build on k10
Add missing files to projects
Updating build.sh based on KRuntime changes
Some refactoring in query in preparation for provider specific SQL gen
Whippersnappers in sidecars... (Initial work on detecting foreign key changes)

Lots still to do here--this is an attempt at a relatively small checkin for the first set of changes that will detect if an FK property has changed and trigger corresponding fixup of navigation properties. The general idea is a sidecar that tracks the last known FK property value such that it can be compared in DetectChanges and used in fixup to remove old references and add new.
Initial support for LINQ method translation on relational. Enables full query suite on SQLite.
SQLite: Uncomment tests that were failing due to aspnet/DataCommon.SQLite#35
Code cleanup
Removed the idempotent SQL generation.
Moved SQL Server specific SQL generation out of the base MigrationOperationSqlGenerator
Renamed ModelDiffer DiffSource and DiffTarget to CreateSchema and DropSchema
Added code to handle transitive renames in ModelDiffer
Updated and added tests.
Performed some cleanup (simplified expressions, , removed unnecessary NotNull annotations - as suggested by Resharper)
Pickled onion munchies... (Additional functional test coverage for fixup)

This change expands the Monster Model so that it:
- Is defined in terms of interfaces with concrete implementations for:
  - Full notification entities (PropertyChanging and PropertyChanged implemented)
  - Entities that only notify for PropertyChanged
  - Normal entities that don't do notifications
- Has additional tests for fixup when FKs change

I did some work to enable the tests for SQLite, but this is currently disabled since Database.EnsureCreated is not working yet.
All your principal belong to me... (Additional fixup testing and support for reference stealing)

Additional unit tests for fixup code that runs when FKs are changed. Also added support for nulling the old dependent FKs and navigation from the old dependent to the principal for one to one relationships when the FK of another entity is set to point to the principal.