It accepts comma separated list of names that are
either string module attributes (ascii_letters,digits, etc)
or are used literally
To enter comma use two commas ',,' somewhere - preferably at the end
Qoutes and double qoutes are not supported
Added new parameter 'encrypt' with same semantics from that of
vars_prompt. When encryption is requested a random salt will be
generated and stored along the password in the form:
'<password> salt=<salt>'.
Also store passwords with an ending '\n' for easier looking at files
with console tools. File content was being already rstripped so this
is harmless.
