curved and sloped brigdes

Planck released his curved and sloped brigdes addon on the official forums. The brigde sections are compatible with the original Resistance bridge section by BIS and use the same textures.

Planck made 3 sections:

- 50 metres long with a 10 degree curve.
- 25 metres long with a 10 degree curve.
- 50 metres long and has a 5 degree slope.