Password getters

[Philip Van Hoof <spam pvanhoof be>]

I refactored the getting of passwords. The reason for this is the
following:

In the good'ol days only TnyAccounts asked the user for a password.
Actually the TnySessionCamel does this, and your TnyAccountStore
implemented asking the password itself.

That was not enough as TnyAccountStores can ask for passwords themselves
(not only on behalf of TnyAccounts): for example the TnyAcapAccountStore
decorator can ask for the ACAP server's password, just to get the
accounts (who will again ask for passwords).

Because I didn't want libtinymail-acap to strictly depend on gtk+, I
made an interface for this: TnyPasswordGetter.

There are two implementations: TnyGnomeKeyringPasswordGetter and
TnyGtkPasswordDialog with the later being the most simple version and
the former using the GNOME Keyring and the GnomePasswordDialog APIs.


-- 
Philip Van Hoof, software developer
home: me at pvanhoof dot be 
gnome: pvanhoof at gnome dot org 
http://www.pvanhoof.be/blog