intellisense keeps rebuilding references Unity C#

[kieferrm]

Moved from microsoft/vscode#9941:

• VSCode Version: Version 1.3.1 (1.3.1)
• OS Version: OSX 10.11.3

Steps to Reproduce:

1. install VSCode
2. write in a Unity C# project

As you type, suddenly intellisense is lost and all the references & auto complete are gone, then a few seconds later they come back. Coding like this is very frustrating as everything moves up and down all the time.

[aukaost]

See also #269

[DustinCampbell]

This should be working better in the 1.5 release.