desktop notifications enhancements and clean-up
Changes in this branch include:
- do not re-use the same GNotification so Balsa can display more thanone at a time
- drop libbalsa_information_parented() which was used in one place only
- optionally add a button to the notification so the user may hide/disable further instances, and store the choices in the config
- add the option for hiding to a few notifications
- simplify initialisation
- fix wrong warning re. a broken Autocrypt: header (see issue #63 (closed))
Note: @peterb's proposal re. shifting the Thread messages option to a more appropriate menu are not included in this MR as this IMO is a separate task which popped up only as I used the opportunity to add the option for hiding a related IMAP server notification.
Signed-off-by: Albrecht Dreß albrecht.dress@netcologne.de