[O] Trying to replace PasswordSafe with org-crypt

[Óscar Fuentes]

After invoking org-encrypt-entry on a header its contents are replaced
with:

* foo :crypt:
-----BEGIN PGP MESSAGE-----
Version: GnuPG v1.4.10 (GNU/Linux)

jA0EAwMC1x9QRUGObPFgySqJXEOiDqi5xGUFqt6GOs0Y2RB7b+euyEy37EVRR32D
HFRSrIchM2MuPcA=
=+O2/
-----END PGP MESSAGE-----

There are several problems with that.

First:

-----BEGIN PGP MESSAGE-----
-----END PGP MESSAGE-----

It would nice to get rid of that noise, if possible.

Second:

Version: GnuPG v1.4.10 (GNU/Linux)

That changes from system to system (GNU/Linux, MinGW32) and gpg version,
which is not good when the file is versioned.

Third, the encryped text changes from invocation to invocation. That
means that the sequence

org-decrypt-entry
<wait for a while>
org-encrypt-entry

alters the cyphertext. Again, this is annoying when the file is under
version control.

Finally, is there a way to force symmetric encryption?

I'm using the org 7.4 that comes with Emacs 24.0.50 (development
sources) on Linux and Windows.