Release 0.7.0

[daviwil]

This changes brings over the Linux and macOS support that I was working on privately before today's launch. Since there's a lot of changes in the integration commit, I'll list the highlights:

• Introduced a new TCP channel to provide a commonly-available communication channel
  across multiple editors and platforms
• PowerShell Script Analyzer integration has been shifted from direct use via DLL to
  consuming the PowerShell module and cmdlets
• Updated code to account for platform differences across Windows and Linux/macOS
• Improved stability of the language service when being used in Sublime Text

I fully expect the CI tests to crash and burn after these changes, so I imagine I'll have a little more work to do :)

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This change is

[daviwil]

Alright, still the same old recurring test failures (not getting the 'terminated' event). Everything else looks solid. I'll go ahead and merge this so that I can move on to getting the build system moved over to compiling the CoreCLR version of PSES.