dump_windows: off-by-1

Change-Id: Iaa6bd350cbc8b07016f7a73a267107431e173e93

Add a dump_windows script to help with automating screenshoting

Oddly hey hangs when asking Pe, someone should investigate.

Change-Id: Ic94d0a2600ceae5f73ce11d5666b6a7abd54c0c0