Fixed swapped left/right sprites for some energy guns.

Just in time to celebrate feature freezing, let's assure one's immersion(_tm_) is not broken by some incorrects sprites.

More seriously, swapped some left/right sprites that were reversed for :
* the energy gun and the taser (all _18_ of them,  fix #3636)
* the disabler (all 6 of them, as those sprites are obviously derived from the taser ones).

Semi-mandatory image :
![swapped](https://cloud.githubusercontent.com/assets/7117411/2907335/1d367a24-d61b-11e3-83d4-bb97e61f9cae.PNG)