Pass version received from AppServer along to the App

The version number sent to the app is now the one received in the PUT. This patch actually accepts request bodies with more than just the version=X string and also accepts repeated version updates, as we can work around those cases.

The only cases that actually correspond to errors are decreasing version numbers. So it is possible to go from version 1 to 23, but then not back to 2.

This should fix issue #25.