Made VMD scripts to generate frustratogram images more useful #16
Description
Frustratogram visualizations can be drawn by VMD much faster if the program is launched in text-only mode.
But the choice of the snapshot renderer in the VMD scripts written by write_tcl_script is incompatible with text-only mode. The program runs without errors, but writes an empty file instead of the image of the frustratogram.
We should switch to the TachyonInternal renderer, which can generate the correct image even when VMD is launched in text-only mode.