klone CFLAGS passed down to libu configure

[thomas-fossati]

I'm not sure this is a bug per se, but certainly is a dangerous feature.

What can happen -- actually did happen, see #4 -- is that if CFLAGS have side effects (e.g., defining / undefining macros) the fact that klone's CFLAGS are used in libu configure checks can end up subverting settings. In #4 , makl_checkinline fails in klone's configure and adds -Dinline= to CFLAGS. Then libu configure is run and its own makl_checkinline is invoked which now passes because in the meantime the inline keyword has been suppressed...