🧐 Motivation

Simple _addPayee is not enough to manage complex splitting logic

📝 Details

Right now there is only _addPayee(payee, shares) function. It's not possible to add more shares, remove shares or remove a payee altogether. Since adding a payee is like adding more shares and removing a payee is like removing all of his/her shares, adding these two function should be enough: _increaseShares(address payee, uint256 shares), _decreaseShares(address payee, uint256 shares).

Also, requiring to specify payees in the constructor limits my use case. I want to be able to make a payment splitter without payees and add payees later(e.g., using something like function addPayee(...) onlyOwner.