Fixed Range Nightvision v0.7

The default high dynamic range while using nightvision in the game is somewhat faulty.
Most of the time you can use it fine, but in some cases it becomes almost unusable.
A light source in view makes the entire screen black or draws a contrast that makes gameplay impossible.
This addon allows disabling the stock hdr engine in nightvision and allows manual adjustment of NVG exposure.

You can configure the addon to your preferences at '<arma2 installation folder>\dta\S_NVG\S_NVG.hpp'

So essentially this is a port of my addon for arma1;
http://www.flashpoint1985.com/cgi-bin/ikonboard311/ikonboard.cgi?s=6faaa176412d2e4e4f83406b659d5ef7;act=ST;f=69;t=72585
Note that while pre-v0.7 versions of the addon still work as-is on A2, it is recommended that you upgrade as it will have key-handler conflicts and might cause breakage

Differences to A1 version;
* It is now disabled by default - A2 HDR is greatly improved from A1, but still has some issues, so this addon needed to be made.
* Much cleaner code.
* Uses A2's new displayEventHandlers, so key conflicts should be gone.
* Put key assignments and default setting in the file \dta\S_NVG\S_NVG.hpp, so those who don't like the defaults can change it
