Incorporated a stage task in a similar fashion to that of the sbt-native-packager. This task performs the asset pipeline delivering its mappings to a target/web/stage folder.

In so doing the scripted test has been simplified by incorporating the stage command.

One last thing - the "stages" and "allStages" tasks have been renamed to avoid any confusion going forward.
Merge pull request #28 from huntc/stage

Stage task