#1. made persisted storage exclusive to 1 process. like before, second VS with same solution will not use persisted storage.
#2, tweaked sqlite to share cache between connections like esent.
#3, made VS and OOP to use different db files (we can make them to share if we want to, but for now, nobody requires it so we create 2 different db)

..

made OOP mock to enable persisted service.

Warn if user replaces a method that overrides a metadata method with a property

Fix issue where Metadata as source wasn't properly handling Xml doc files with LF newlines.

* Use 'default' over 'default(T)'

* Update BreakpointSpans.cs

* Update DeclarationNameCompletionProvider.DeclarationInfo.cs

* Update BreakpointSpans.cs

* Update DeclarationNameCompletionProvider.DeclarationInfo.cs

* Update DeclarationNameCompletionProvider.DeclarationInfo.cs

* Update DeclarationNameCompletionProvider.DeclarationInfo.cs

* Update BreakpointSpans.cs

Fix error handling in unit tests

Correct comment about parameterized property

Merged on behalf of @svick 
Thanks for the contribution!

Fix crash when encountering a parenthesized expression when converting an 'if' to a 'switch'

made NFW to use normal watson if given exception is non recoverable exception in OOP

* Clean up Concord exception utilities

* Avoid dependency on IL stream in EnC local slot mapping

* Fix lambda EnC

removed left out from deleted esent code.

Replace project reference with linked file

Switch to a direct walk up the tree.

this makes OOM to crash OOP process. this won't crash VS, instead it will show info bar and notify users to close VS and re-open.

Move LambdaRewriter MakeFrames into Analysis

The frame creation pass now considers scope of captured variable
introduction instead of closure creation, so the ordering can change if
two or more nested functions access variables 'outside-in', e.g.

```csharp
{
    int x = 0;
    {
        int y = 0;
        int L1() => y;

        {
             int z = 0;
             int L2() => x;
        }
    }
}
```

If we visit closures in-order in the previous example, we create frames
for L1, then L2. If we visit captured variables scopes, however, we
visit `x` (captured by L2), then `y` (captued by L1).

This is part of the effort to move as much logic from LambdaRewriter
into Analysis as possible. The more logic there is in the Rewriter, the
more difficult it is to find calculation problems until the last
possible moment, and it's also very difficult to calculate useful
information for later analysis passes, like the final debug and closure
IDs for each environment.

ExpressionEvaluatorPackage was depending upon ServicesVisualStudioImpl
to get the references for ProvideRoslynBindingRedirection.cs that it
was building itself. This is somewhat terrifying as that's an assembly
dependency that at runtime isn't allowed to exist, so let's be explicit.

Add feature to add missing File-Banner to a file.

Use 15.3 Preview 7 for VSI CI machines

Add StrongName to list of language features

Fix where

Work around SDK 1.1 issue around netcoreapp2.0