Update all four PreBuildEvent configurations (Debug Win32, Debug x64, Release Win32, Release x64) in the vs2017 wren.vcxproj to call the new update_deps.py and build_libuv.py scripts instead of the removed libuv.py download and build commands. Also append "vs2017" argument to the vcbuild.bat call in build_libuv_windows function to ensure correct toolchain selection.