Extra space is needed in echo -n "-lncurses ", otherwise if pkg-config outputs a directory after that, it will result in "-lncurses-L/opt/local/lib" (without space).
-Wno-format-security flag is needed on macOS to silence warnings about printf(gettext("message")) constructs.
Used by mbedTLS to set MBEDTLS_CONFIG_FILE in all components.
This change sets CFLAGS/etc at the project level and then exports those
variables for components, rather than setting them independently each time
a component Makefile is invoked.