Most importantly, the separate command line options for switching on the legacy buffer handling have been removed.
There's really no need for them anymore, because unlike in earlier versions many of the implementation differences no longer exist - with the exception of where the light and vertex buffer contents are generated.
For testing this, -glversion 3 is sufficient.
This was already disabled for GL 4.4 and lower but also needs to be done for Intel's GL 4.5 drivers.
Unlike before this is now exclusive to the light buffer, the shadowmap feature is not affected anymore, although that should be impossible to use anyway on all affected hardware due to lack of computing power.
This removes 3 uniforms, consisting of 9 floats. Those were merged into other values that never get used at the same time.
It also moves the costly setup of the fixed colormap out of the render state into the 2D processing code.
Since 3D forces use of render buffers now, it is no longer necessary to draw the entire scene with the colormap active, meaning it can be handled more efficiently.
The fixed colormap is a per-scene global setting that normally does not need to change ever during rendering of a scene so it's easily shoved aside into a static uniform buffer.
Having to change this buffer for inconsequential stuff should be avoided, especially when there's other uniforms that are just as good to hold these values.
These files are not part of the actual renderer but part of the system code.
This means, for separated modern and legacy GL renderers, there still will only be one set of this, unlike everything else.
