.Net Core: remove floating versions (use stable ones on Nuget.org) and get this puppy back in action.

Also: it's 2016.

This reverts commit 70ee9a72.

Bumping dependencies version numbers

Heh, AspNet and DNX (only) work in VS2015; DNX and DotNet (only) work in VS15; I guess we need to use DNX for now, then, as the only one that works in both.

Recreate all the xproj to reflect the current tooling - old versions break VS15; enable XDocument etc in corefx (#if block was too large)

When doing list expansions (6=>10 etc), use the last non-trivial value - do *NOT* use null, as it causes problems with "not in" clauses; add test for the same

Readme.md: update performance benchmarks tests broken link

prefer an exact-case backing-field match over a wrong-case regular field (essentially: this promotes get-only properties over regular fields)

Update to sqlite rc2, because without that nothing works; add extra tests around sqlite oddities; update tests to reflect sqlite rc2 fixes

Add SQLITE to test builds; add tests for issues #466 and #467; fix #466 by adding retry-with-fallback flags strategy

Fix typos in the comments for PadListExpansions

New feature: PadListExpansions - reduces query plan saturation by padding "in" lists and populating with nulls; opt-in (see remarks on setting)

Initial test setup for #461; note that this does not repro, due to running on SQL-Server - needs to be changed to SQLite to repro

actual/expected in asserts are the wrong way round

All the tests are wrote in the form actual.IsEqualTo(expected). This
made for some odd error messages when a test failed.