issue #3823: Removes curl libraries for linux. It was installed by 'apt-get'.
issue #3823: Removes glfw, curl include and library path. They are installed to system.
issue #3823: install_glfw.sh will not skip if it was installed. Since it will not be updated if we find a new version of glfw.
BTW, install script will not be invoked in every build after we switch to cmake.