* lisp/gnus-offline.el: Rewrite to work with pGnus v0.74 based T-gnus.

* lisp/gnus-offline.el: Rewrite to work with pGnus v0.74 based T-gnus.
* lisp/gnus-ofsetup.el: Ditto.
* lisp/pop3-fma.el: Removed because after pGnus0.73 , pGnus can treat multiple
pop3 account.
* lisp/read-password.el: New file.
* lisp/gnus.el (running-pterodactyl-gnus-0_73-or-later): Provide as a new
feature.
* lisp/mail-source.el (mail-source-read-passwd): Don't load "passwd" if the
function `read-passwd' already exists.
* lisp/gnus-start.el (gnus-read-active-file): Eliminate duplicated select
methods.
* lisp/gnus-group.el (gnus-group-catchup-current): Fix typo.
* lisp/gnus.el (gnus-version-number): Update to 6.10.056.
* Sync up with Pterodactyl Gnus v0.74.