Overhead stab bug

[oposum]

Yesterday I was doing some testing in NI, accidentally I discovered that overhead stabs behaves weirdly. More specifically, as was the case in Napoleonic Wars, overhead stab uses the same timings and damage calculations which overhead swing uses. This leads to weird behaviour (negative speed bonus when moving into the stab, shorter range than the mesh shows, instahits, lower damage than usual). While it isn't horrible, it would be nice if it was fixed