write-host now sends output to hipchat in real-time

[mikeclayton]

Updated AutoBotHost and PowerShellRunner so that using write-host in scripts results in the text being sent to HipChat there and then, rather than waiting for the script to finish running. This allows the script to report on progress for long-running tasks (although it might get a bit spammy if used too much).

Try this script to see the result:

function Get-WriteHostOutput {
write-host "starting up...";
for( $i = 1; $i -lt 10; $i++ )
{
write-host "test message $i";
[System.Threading.Thread]::Sleep(2000);
}
return "done!";
}

TODO: The PowerShellRunner class is becoming a bit of a dumping ground for the glue code so it might need to be cleaned up as a separate commit.