v2.4.0

Added

• @ethersproject/bignumber, decimal.js, evm-bn, and mathjs as normal deps.
• Ship JavaScript source maps with the npm package.

Changed

• Americanize spellings in NatSpec comments.
• Move everything from the prb-math.js package to prb-math.
• Polish NatSpec comments in avg function.
• Use underscores in number literals.

Fixed

• Bug in powu function in the PRBMathSD59x18 contract, which caused the result to be positive even if the base was negative.
• Minor bug in avg function in the PRBMathSD59x18 contract, which rounded down the result instead of up when the intermediary sum was negative.