Prerelease Kappa v1.3.0

Added:
- calc.d2fdx2(func, val)
- calc.tangent(func, val)
- calc.normal(func, val)
- calc.binormal(func, val)
- calc.dfrdt(func_1, func_2, val)
- calc.grad2(funcORvecfield, vec)
- calc.curvature(func, val)

Removed:
- Nothing

Changed:
- real.function(definition, type)
- real.val(func, val)
- plot.function(func, scl, rgba, domain, origin, weight, context)
- calc.dfdx(func, val)
- calc.fxdx(func, val)
- calc.dfdv(func, vec2_pos, vec2_dir)
- calc.grad(funcORvecfield, vec)
- calc.frdt(funcORvecfield, func, a, b)
- calc.fds(func, a, b, c, d)
- calc..fnds(vecfield, func, a, b, c, d)