Webscript test runner

#203 - Use webscript for Integration Tests rather than embedded Jetty

This pull request adds the new JUnit runner and webscript infrastructure to alfresco-rad. It has been integrated into the repo amp archetype. It has not been integrated into the aio archetype and hence will have broken testing there until that is remedied.

There are a few additional items in here like:
* started CONTRIBUTE.md to root, needs updating
* updated run.sh to pass arguments on to the mvn command for all archetypes
* added debug.sh to all archetypes that uses mvnDebug instead of mvn
* gab added a top level property: alfresco.default.version from my machine

There are some placeholders for the test listing web script but most of it is commented out as that has not been implemented yet.

Additionally there is a comment in: archetypes/alfresco-amp-archetype/src/main/resources/archetype-resources/pom.xml that should be looked at by Gab.