Separated GUI from backend. Fixed namespace inconsistency.

Not the cleanest solution ever. I *suppose* it works as before, but I
don't have Guild Wars 2 on my development machine. The GUI and backend
are still interdependent, which is a shame, but at least they are now
separated in classes. updateMap() might need a better solution to
updating UI elements than putting strings in a dictionary. GlobalVars
has been removed in favour of just actually making them global
variables.

Also fixed a namespace inconsistency. If this is not merged, I highly
advise changing all "Gw2Mapping" namespaces to "Gw2MappingLink". This
can be done - I believe, by renaming "Gw2Mapping" in the solution
explorer, but can also be done manually.