hwaf-base: deprecate copy_uselib_defs -> hwaf_copy_uselib_defs
find-toolchain: support for correctly overriding a C/C++ toolchain
find-lcg: correctly expand ctx.options.with_lcg + fixed typo
hwaf-base: correctly expand vars/path in check_with
hwaf-base: add hwaf_propagate_uselib (so cross-project use-lib propagation work)