[2.2.0] My patch for more secure passwords

[bjmg]

Hi,

as promised here is my patch for more secure passwords.
It now uses a correct md5 encryption and a better salt (more secure) for the standard encryption (DES).
Also .htpasswd files are generated with MD5 encryption (if enabled). This is completely new.
The mailuser backend now also supports MD5 encryption. This is completely new too.

I hope I did not make any mistakes. At least I think the code works good.

To patch your installation you have to do the following:
copy the file in the attachment to /home/admispconfig/ispconfig
run the command: patch --dry-run -p1 -i secure-passwords.txt
If there was NO error run the command:
patch -p1 -i secure-passwords.txt
That's it!

Before I forget it:
DON'T TRUST ANY EXTERNAL CODE WITHOUT PROOF READING IT.
(And not in any case if it changes something on encryption functions.)

Bernhard