This introduces support to overlay FCAT markers on top of other HUD elements.
For more information about nVidia's FCAT tool see: https://nvidia.com/en-us/geforce/technologies/fcat/technology
This patch includes support for the existing parameter infrastructure and it is fully dynamic.
Squashed commit:
Refactor FCAT to use existing parameter handling infrastructure
With this patch the FCAT overlay should be hooked up into the normal
parameter handling infrastructure. This includes support for
configuration file options, which are also part of this commit.
