assettools: correct url for description
assettools: generate .j3m to be able to update texture path
ModelExtractor: more defensive against null
publisher0:  restructure build.gradle
- replace task 'prepare' by 'assemble' to match java project 
- use a allprojects{...} section
- top priority for mavenLocal repository
- fix order when 'downloadFile' task is used with 'unarchive' task
experiment auto detection of subproject by subfolder existance (in our case non exists on master repo)