Space-age composite polymer; not a shred of sqlmetal... (Support composite keys end-to-end)

This change adds support for value generation with composite keys which was blocking use of composite keys end-to-end. The state entry will now generate values for any property marked to have value generation on add regardless of whether that property is part of a key, composite or not.
You can't fire me because I quit! (Change from Added to Deleted results in detached entity)

See issue #351. When an entity is in the Added state it means that it doesn't exist in the database and should be inserted during SaveChanges. If the state is then changed to Deleted this would mean delete an entity that doesn't exist in the database, which will fail. In the EF6 stack we instead detach the entity in this case so that it is just never inserted. This change implements the same behavior in EF7.
Add csproj to sln and add skeleton code rowanmiller
Beginnings of a provider for Azure Table Storage.

Add null checks on public interfaces.
Batching is now configured per context.
Wrap Azure SDK in more testable interfaces and wrappers. Fix async issues on fetching
Update datastore to match new API.
Minor tweaks. Change batching setup to use configuration.
Whitespace fixes (R# code cleanup)
Implement HasTables. Add strings resource and check utilities. Wrap the CloudtTableClient in a testable interface
Add TODOs and more whitespace corrections
Culture invariant dates and other minor tweaks.
Add functional and unit testing to ATS requests. Enhance error handling.
Merge pull request #181 from natemcmaster/ats

Beginnings of a provider for Azure Table Storage.
Adds support for server-side filtering of data types supported by ATS.
Rebase on dev
Renamed class to match convention and other fixes.
Merge pull request #267 from natemcmaster/AzureTableStorage

Adds server-side filtering
POCO support for AzureTableStorage