The only thing that doesn't work yet is the system-settings service's
"auto eth" connections for ethernet devices that don't have an existing
connection. Might also have issues with unmanaged devices that can't
provide a MAC address until they are brought up, but we'll see.
Instead of requiring applets to hash passphrases, just do it in NM instead.
This should fix confusion where people don't understand that they are seeing
their hashed passphrase.
Use AC_GNU_SOURCE macro instead of setting -D_GNU_SOURCE manually.
The macro will add the _GNU_SOURCE define to config.h for systems that
have the GNU extensions.
