Added kcm ui with global and app-specific config options.
Global options affect all notifications:
- Persistent only? --> Sync only notifications with timeout == 0?
- Include body? --> Add body string to summary when syncing?
- Minimum urgency
Per-application options affect notifications sent by a specific
application:
- Sync it at all?
- If yes, allow to define a "blacklist" pattern (QRegularExpression)
to define which notifications should *not* be synced.
Applications are maintained in the per-device config and added when
seen the first time by the notification listener. From that moment on
they can be configured in the kcm ui.
Centralizing the plugins' config will ensure that all the plugins store it
the same way (ie: not in random files scattered around, like until now).
The base KCM class, together with the already existing base plugin class,
will give easy access to all the plugins to this centralized config. Also,
now the settings are not shared across devices (that is: every device can
have different config for a same plugin).
Note: This commit requires KCMUtils 5.9
REVIEW: 122927
