Move error handling to front-end, make standardized extra error codes to interpret from.

[4shub]

Right now hackmerced handles all of the error messages on Tomoe, which doesn't make sense since Tomoe is just an API - why do we have to go to Tomoe to change our error messages on our website?

We need to create a standardized error system that can be interpreted by us (and others) so that the error messages we want can be just set inside of HackMerced's or any other hackathon's website. This is especially helpful in internationalization, since Tomoe won't be responsible for translating everything and also sanity, so we don't need to standardize everything with Tomoe.

[4shub]

Halfway done...