We need error messages for revert(), require(), and assert()

[GriffGreen]

The entire contract needs to utilize solidity's new functionality. This might be a fun way to let community members contribute to the project.

Each error message should be it's own PR.

See https://media.consensys.net/when-to-use-revert-assert-and-require-in-solidity-61fb2c0e5a57 for more background info

[djudjuu]

hey @GriffGreen ,
let's specidy this a bit more: What style do you want those error-messages to be

example: require(donorAddress != 0); could be

a) donor address must not be zero
b) donor address should be nonzero
c) donor address is zero address

plus variations on capitalization and punctuation (dots at the end or not?)