[Tracker] Tracker system tray

[Erlend Davidson <erlend davidson gmail com>]

When you hover your mouse over the tracker magnifying glass icon you see 
a yellow tooltip... When it says "Tracker: paused by system" I think it 
would be useful to see why.  For example: "Tracker: paused by system 
(reason: system still booting)".  On a similar note I do think it could 
do with more statistics too: instead of "Indexing 1/1 folder" it could 
list all the things it indexes and whether they are up-to-date.

Thanks,

Erlend