Test version

Put libGL.so.1 to target system and specify LD_LIBRARY_PATH
Use VTEST_DT_OPTIONS=help to get displaytarget options
Use VTEST_SOCK=<path> to specify socket path and VTEST_RING=1 to enable ring buffer
Use :<port> instead of socket path for tcp mode
force-3.0 version skips checking 3.1 context as it breaks shaders on adreno
mesa configuration:

meson . build -Dgallium-va=false -Ddri-drivers= -Dgallium-drivers=virgl -Ddri3=false -Dvulkan-drivers= -Dglx=gallium-xlib -Dplatforms=x11 -Dtools