Fixed issue with Write-Progress

Write-Progress would throw an error when running in the new PowerShell host.

Additional Logging to PowerShell Host and Host Startup

Additional logging has been added to help diagnosis startup issues. Logging will be written to:

%AppData%\PowerShell Tools for Visual Studio

Hang when typing

The tokenizer could cause Visual Studio to hang when typing.

Hang when writing to the screen

Fixed a potential hang when the PowerShell host would write to the screen.

Hang when PowerShell Interactive Window was loading

Fixed some threading issues within the PowerShell Interactive Window that would cause a hang if it was open while Visual Studio was starting.

Fixed PowerShell Crash when existing Visual Studio

PowerShell would crash when exiting Visual Studio due to a Null Reference exception.