r275 Bug Fixes and new Installer

To hopefully quell installation issues there is a new installer that requires a MC login but ensures a fresh copy of minecraft.jar is used and all files get put in the proper places.

• Fixed crash bug involving being hit by an arrow without an item equipped in one of the hands
• Fixed 3d grass looking weird when being hit
• Fixed an odd dark pixel in the 3d grass so it no longer stands out so much

No Maps - http://www.mediafire.com/?6an1k1bzlveea1w
With Maps - http://www.mediafire.com/?rmrg4pxgb3szi7g

Edit: Note the offline installer was broken in the previous downloads due to some files in the .minecraft\bin directory being marked as read only.