Can't leave the backup files lying around when doing 'make distcheck',
so when backup up a file, return the backup file path so that the
caller can (optionally) remove it.
If the certificate path from the supplicant config is not absolute,
we need to make it absolute. When building with a different builddir,
the certificate from the supplicant config is actually in the srcdir,
but the builddir is the current PWD.
The ctype macros (eg, isalnum(), tolower()) are locale-dependent. Use
glib's ASCII-only versions instead.
Also, replace isascii() with g_ascii_isprint(), since isascii()
accepts control characters, which isn't what the code wanted in any of
the places where it was using it.
Always removing wep_tx_keyidx will cause wpa_supplicant.conf being
written even if nothing has been changed. Now it will be removed only
when wep is not used anymore.
nm_utils_hwaddr_ntoa() and nm_utils_hwaddr_aton() are like
ether_ntoa()/ether_aton(), but handle IPoIB too.
nm_utils_hwaddr_atoba() is like _aton() but returns a GByteArray,
since that's what's wanted in many places.
Also remove nm_ether_ntop() and replace uses of it with
nm_utils_hwaddr_ntoa().
