* remaining vector class documentation (this should be all now)
 * added proper constexpr vector subscript support if the index is known to be const and in [0, #components - 1] (this is done via clangs enable_if extension)
 * added distance_squared to the vector class (simply dot(b - a, b - a), might be useful and prevents a sqrt)
 * added relational vector comparison functions with an epsilon for component-wise comparisons (is_*_vec, I didn't add these the first time because of the necessary different name, since they only differ in return type from the other is_* with epsilon comparisons)
 * added + use FLOAT_NE_EPS macro, floating point unequal/not-equal with an epsilon (true if "x < val - eps || x > val + eps")