Rewrote Vector2.lua and cleaned other Lua files

About the new Vector2: Everything was rewritten and tested (the exception of testing would be anything commented out). You should really read over all the comments that have three `-`s (as opposed to two) because the information they contain is pretty notable.

A nice thing about the new Vector2 is that you don't have to do `vec1:add(vec2)` but instead you can do `vec1 = vec1 + vec2` thanks to metatables. You can also now do == comparison and `#vec2` to get the length, aka magnitude, of a vector2.

As for "other Lua files," I cleaned up every champion's files to be readable and work with the new Vector2.lua that I wrote.