Cursor position error on osx (and linux?)

[ChrisPritchard]

Console writing is not aligned properly on osx. Each char typed jumps to a new line. Test and resolve.

[ChrisPritchard]

this is an issue on linux too. great. makes fixing it easier at least

[ChrisPritchard]

For now, though its not ideal, I have disabled the line clearing functionality on non windows platforms. This causes a problem when using up/down to go through history, though the problem is purely cosmetic.

[ChrisPritchard]

I have restored line clearing with a slight change. the issue seems to be related to cursor top and left functionality on unix (some notes in the source about this, here: https://github.com/dotnet/corefx/blob/master/src/System.Console/src/System/ConsolePal.Unix.cs)