Compiler error on LineSeries.Smooth when updating to unstable version

[Dunkhan]

Steps to reproduce

1. Create a plot with a lineseries set to mySeries.Smooth = true; in the current stable version
2. Update the oxyplot dll to the newest stable release
3. Attempt to compile the project

Platform:WPF Win10
.NET version: 4.5.2

Expected behaviour

This is a minor issue, it is probably inteded to force the user to change the code.
The correct behaviour would be for LineSeries.Smooth to compile but to have a compiler deprecated warning instead.
e.g. [System.Obsolete("LineSeries.Smooth is deprecated, please use LineSeries.InterpolationAlgorithm instead.")]

Actual behaviour

The compiler does not recognise LineSeries.Smooth and fails to compile

[objorke]

Should (2) be update to newest unstable release?
Since the newest unstable release has a major version change, we can have such breaking changes.