the problem about using libraries: Safemath and String

[ericlewis966]

In this project, I used Safemath for all arithmetical calculations in each smart contract.
But to be honestly, we don't have to use Safemath in the 0.8.0+ versions of smart contract.
Cause in this version of smart contracts are supporting built-in funtionalities to prevent the underflow and overflow issues.
If someone keep using Safemath in 0.8.0+ version of solidity smart contracts, It has bad effect for the memory using and the security completion.

On the countary, I used customized uintToString() function in some functions, but It also unnecessary.
Because the String library is currently supporting toString() function for all data types.

Hope you are using this project with right concept and optimized env.