Configurable projection and tested with different projections

[crangelsmith]

I've made the projection now configurable and defaulting to BNG if not configuration is given. The issue I see atm is that a lot of the name formatting now is assuming BNG, and needs to be adapted if is not (it can look weird in lat long). I think options for this can be added later on once we are tyding out the code given that we only care about BNG for this project.

Originally posted by @crangelsmith in #29 (comment)