* Fixed nil pointer in Copy()
* Position added
Added Floor() and String() methods to Vector.
Also added Position which declares an embedded Vector2 and returns various forms of it.
* d2vector.Vector2 renamed to d2vector.BigFloat
* vector.go renamed to big_float.go
* Float64 stub and more renaming
* Vector value getters
* Separate vector types with initial methods.
* Divide and lint warnings.
* Distance and Length.
* Scale, Abs and Negate.
* CompareFloat64Fuzzy delta direction reversed.
* Refactor vector_test.go.
* Renamed Approx methods.
* Distance and Length.
* Distance and Length.
* Removed BigFloat and Vector, renamed Float64 to Vector, simplified tests.
* Angle, SignedAngle and other small functions.
* Receiver rename.
* SingedAngle and test fixed
* Rotate.
* SetLength.
* Cross.
* NinetyAnti and NinetyClock.
* Lerp and Clamp.
* Reflect and ReflectSurface.
* Cardinal convenience functions.
* Comments.
* Panic on NaN and Inf in Position.
* Lint warnings and comments.
