Modify windows bat launcher to cd to the location of the bat file.

[tmheath]

From my windows laptop at work this does not seem usable outside of the folder downloaded. To fix I added a cd %~dp0 line in the middle there. I will probably move to fix it once I'm home tonight, unless it is already fixed or told it's desired behavior for some reason. The only downside to doing this is that it modifies the calling command prompt, though this seems to be a non-issue as the calling command prompt is consumed at start.