Ok. So in order to have a file one needs to run as well:
git clone https://github.com/EOSIO/eosjs.git
npm run build_browser
// builds: ./dist/eos.js
The fact is that it does not work on Windows. If you try better run on Linux
The eosio.token contract is indeed for the public to create tokens on, similar to ERC20 on Ethereum however instead of a contract for each token, many tokens can be based all on this one eosio.token contract.
Part of the eosio.system contracts README.md is as follows...
"This contract enables users to stake tokens, and then configure and vote on ...
It's worth it. They changed a lot of stuff as you can see on the release page: https://github.com/EOSIO/eos/releases/tag/dawn-v4.1.0
The procedure that I usually run:
# from the eos root folder
rm -rf build
cd build && sudo make install
That's it! If you are using contracts with account_name change it to name and recompile it, so ...