Stop calling IVsHerarchy.ParseCanonicalName if we don't need it

* Only import package versions in projects that restore toolset packages

* Add nuget.org feed

Resolve function to native offset uint.MaxValue

Don't push an empty batch of projects

Previously the FunctionResolver used 0 for the native offset of all
instruction address of resolved function names. The debugger inteprets
this literally, which causes function BP's to be bound on the first
native instruciton of a JIT'd method. This is incorrect as the bp should
be bound to the native instruction that represents IL offset zero. The
function resolver should use uint.MaxValue for native offset to
communicate that the instruction address always represents IL offset 0,
even for a JIT'd method.

Fix bugs related to IAnonymousObjectCreationOperation

Avoid stealing focus from the active output window pane

Rename KeyValuePair

The target framework netcoreapp2.0 includes a new type: `KeyValuePair`.
This conflicts with our `KeyValuePair` utility class and causes a lot of
friction whenever netcoreapp2.0 is added as a target framework for a
project.

Renaming the type to `KeyValuePairUtil` to remove the ambiguity.

Enable C# semantic tests on CoreClr

The syntax is incorrect and it's failing bash. Will try again later.

Make "Roslyn" default setup project

This isn't used by anything else.

Update CSharpFullyQualifyCodeFixProvider to support unbound identifier diagnostics

Simplify impl of 'prefer predefined type'

Check for invalid file paths in ContainsChildrenGraphQuery

Implement INavigateToItemProvider2 with filtering

Reduces the implicit double check for invalid characters in the path.

Fix target instance selection for integration tests run from test explorer

Enable VB symbols test on CoreClr

Fix a build warning related to an unused event that implements an interface event

Update 'use conditional expression' to work for 'yield' statements.

Use a synthesized local for the lockTaken parameter and create a region for it

Fix spanish build

Avoid producing a new tag tree for buffers that aren't part of the SpansToTag

By default, VS sets the first project listed in the solution as the default project. This saves new contributors from having to manually set the default project.