ifcfg-rh wasn't updated for WEP passphrases after that capability
got added. Can't use KEY for passphrases since there's no way
to distinguish some WEP passphrases from some WEP Hex and ASCII
keys, so we use KEY_PASSPHRASE instead.
Since one test read in a file, wrote it out, and read it in again, we
have to be careful of whether srcdir == builddir or not. If it doesn't,
then we need to remove the written-out connection file. If it does, then
we don't want to remove that written-out connection file because it's
tracked by SCM. Avoid the whole problem by writing it out to a separate
directory that we can always delete it from.
TLS uses the 'identity' which previously wasn't read. The private key
password should also only be used for PKCS#12 files, becuase they aren't
decrypted when read into the setting.
Private keys also need to be handled differently; PKCS#12 keys are written
out unchanged (ie, still encrypted) with their corresponding private key.
DER keys are stored in the setting unencrypted, so they are re-encrypted
before being written out to disk. But because the private key password
isn't known for DER keys, a random password must be used to re-encrypt
the key.
