Sub task of SOLR-6806
The dist/ folder contains many duplicate jar files, totalling 10,5M:
The rest of the files in dist/ are contrib jars and test-framework.
To weed out the duplicates and save 10,5M, we can simply add a dist/README.md file listing what jar files are located where. The file could also contain a bash one-liner to copy them to the dist folder. Another possibility is to ship the binary release tarball with symlinks in the dist folder, and advise people to use cp -RL dist mydist which will make a copy with the real files. Downside is that this won't work for ZIP archives that do not preserve symlinks, and neither on Windows.