Modifications for 0.4.4

In case it is of any help: I have made the (very few) modifications that are necessary for SDK version 0.4.4.

I have also made the required modifications to build the project with SBT in addition to Maven. This allows to launch the demos cross platform just via `sbt run`.
I try to avoid checking in .gitignore files to my repositories.  Files I want ignored tend to go into a global ignore file in my home directory, because too many build tools will generate too many different potential ignore rules.