Preview Transform changes to handle publish profiles

[mlintell]

I often end up using publish profles to extend the build configurations. For example I may have a Debug build configuration with Debug.Dev and Debug.Test publish profiles. However if you invoke Preview Transform on, for example, App.Debug.Dev.config then the base App.Config only gets transformed by App.Debug.Dev.config. IMHO the expected behaviour would be to transform App.config with App.Debug.config and then App.Debug.Dev.config.

So I rolled up my sleeves and added code to handle publish profile based transforms. The code was done fairly quickly but is I hope to a reasonable standard. Anyway, here are the changes I made for your consideration and review. No offence taken if you consider this feature superfluous.