Add wheel rotation lock to Gimx configs.

[crowbarmaster]

Hello and good day Matlo!

I want to start out with a thank you for the wonderful piece of software you wrote for the world to enjoy. I have been using GIMX for a few weeks now with a home-built adapter, and it works well!

However, nothing is ever perfect. I was pretty well used to drifting in GT6 under the 540* setting available with the button combo on my G27. So when I fired up GT7 for the first time to find out this was not an option, I panicked a bit. After having a look around at the source, I had found that your layout for haptic_tweaks spelled out a switch case for RANGE. Perfect, I now had a hard-coded version of GIMX for 540* lock.

I spent the couple days figuring out CodeBlocks and wxSmith as I desired more and more to share this. I had seen quite a few posts asking if this was possible, so I wanted to put some effort down to help ease this request. Gimx-Config now includes a separate control in the FFB Tweaks tab to control wheel rotation ceiling, mirrored logic to FFBTweaks. This creates a whole new node within the config to avoid conflicts with existing configs, structured like so:

      <wheel_settings>
        <device type="joystick" id="0" name="Logitech G27 Racing Wheel USB"/>
        <wheel_rotation degrees="540"/>
      </wheel_settings>

Please, have a look at my PR here, feel free to criticize my work as you feel necessary. C/C++ is not my primary language. Some technical details here, I added a whole new node to the XML configs to avoid causing issues with currently modified config files. I have done some basic debugging and everything seems to work as intended.