README.org: Fixed keybinding for mime map

What I had previously was *unsetting* all the other mime-related
commands.
Use map-y-or-n-p for attachment actions

gnorb-org.el: Both `gnorb-org-handle-mail' and `gnorb-org-email-subtree'

gnorb-gnus.el: `gnorb-gnus-capture-attach'
Note future mail-search-from-agenda function
Merge gnorb-org-handle-mail functions

gnorb.org.el: There used to be two separate functions for agenda and
non-agenda use. No reason for that...
New gnorb-org-capture-collect-link-p option

gnorb-org.el: Set to t to make the capture process always store a link
to the Gnus message or BBDB record under point.
Various README.org tweaks
Open link from string correctly

gnorb-org.el: gnorb-org-extract-mail-stuff

org-open-link-from-string has been changed to use org-elements, and now
needs brackets around the link string.
Many pointless defstructs

No reason they shouldn't be defuns, this is not even remotely
performance critical.
Handle return from mail sending better

gnorb-org.el: gnorb-org-restore-after-send

Needed better checks regarding where we were coming from originally.
gnorb-org-mail-todos -- new docstring and default

gnorb-org.el: gnorb-org-mail-todos
Commenting out my re-implementation of map-y-or-n-p

They've got a better built-in one...
Delete previous commented function