Good, I took some time today to proceed, this I have achieved so far:
1. Plugin is now compatible to Snow Flat Theme of q2a v1.7 (needed JS and CSS hacks)
2. Added admin option to decide if links from notification box open in new browser tab or not
3. Plugin uses CSS now to display icons in notification window instead of img tags, no path problems anymore
4. all images have been combined into one sprite (only 1 request with 3 kb now), loads faster :)
5. Added Lithuanian language
6. Refactored the jquery code: improved inserting of notification box, now not anymore inside the a..qa-history-new-event-link but after() it, and added hack for snow flat theme to move the (N) outside of the user's drop down.
7. More CSS changes because we have a new div #osn-box now, that contains all elements
8. Set Plugin version from 1.1 to 1.2
Download version 1.2 from plugin page: http://www.q2apro.com/plugins/on-site-notifications (click on "Download Plugin")
or browse code on Github: https://github.com/q2apro/q2apro-on-site-notifications/
Track changes: https://github.com/q2apro/q2apro-on-site-notifications/commit/96968f79f49c6d062125142325308e2a5192eeb2
Beta! Please test this version before production installation. Feedback welcome.