add unique style for landuse military

Replaces default green with red stroke with diagonal line pattern fill for 'landuse-military' polygons:
![screen shot 2014-04-14 at 3 49 57 pm](https://cloud.githubusercontent.com/assets/108094/2700002/0f2205a8-c40e-11e3-9458-fb7897e88d17.png)

References https://github.com/openstreetmap/iD/issues/2177