Modified the math/vector.h

Fix #2 VS2019 cannot compile the project

Fix the issue of link error under Windows

Update tgafunc library

Fix issues in save_image() function

Update CMakeLists.txt

Improve save_image() function in image utilities

Update README.md

Update CMakeLists.txt

Update README.md

Update README.md

Update README.md

Update README.md

Remove cwalk library

Add set_clear_color() function