Use gradle for building the bundles

[at055612]

We could use gradle to build the content zips and possibly use it to manage the dependencies. May be able to have each script as a sub-project in gradle so inter-project dependencies can be defined. This may allow us to have multiple script versions, e.g. commonV1, commonV2 etc with different visualisations depending on different versions of common.

Gradle would need to do all the defintion and substitution of the UUIDs.