One Directional Windows Take Priority Over Mobs for Bullets

[Artouris]

Bug Description:
When shooting a mob (human or xeno, for xeno for sure) and they're standing on a table with directional glass, the bullet or projectile will hit the directional glass as if it was a full tile of glass or the glass is somehow taking priority over the mob.

Steps to reproduce:
1. Put Mob in a tile with one directional glass
2. Shoot at mob
3. Watch as glass absorbs bullets even if your shooting through the open space parts.

[phil235]

Projectile code forgets to check if the obstacle is a border one.