Batch mode should support multiple UIDs and subkeys, and ECC too.

This would make batch mode infinitely more useful, and provide a simple-to-write
and simple-to-read method of creating more complex keys. For example, something
like this should work:

Key-Type: ECC
Key-Param: Curve25519
Key-Usage: C
Expire-Date: 1y
UID: John Smith <john@smith.net>
UID: John Smith <john@smith.com>
Subkey-Type: ECC
Subkey-Param: Curve25519
Subkey-Usage: S
Expire-Date: 1y
Subkey-Type: ECC
Subkey-Param: Curve25519
Subkey-Usage: A
Expire-Date: 1y
Subkey-Type: Elgamal
Subkey-Length: 4096
Subkey-Usage: E
Expire-Date: 6m

A subsequent step would be to specify policy/notation as well.