Make it possible to configure the delay for GraphUpdated

Helps fixing JB# 11570
Set the default delay for GraphUpdated to 350 instead of upstream default of 1000

Helps fixing JB# 11570
Add detecting when an image is album art and annotating thi
miner-fs: initialize timers as stopped

This way timers are in agreement with their boolean guards,
and will get continued when processing actually starts.
Merge pull request #13 from pvanhoof/master

Make it possible to configure the delay for GraphUpdated