Create Parser Error/Warning Collector

[lightsofapollo]

@kewisch We touched on this briefly. I believe the idea was to have a warning collection with the optional capability of turning those warnings into errors (or the other way around) right now we throw a lot of errors.

An example of this that I ran into recently is utc offset -0000 which was assigned an error where I believe a warning would have been better. I found that Yahoo (when in etc/gmt) will return this offset. I removed the error in my development branch.