move shutdown of svc services to svc down script
improve sysdetails for extra sanity monitoring

add hard coded sanity check before writing info out ...
* check once a second, not every 100ms
* keep 1800 dumps - that are 30 minutes
* filter processes - only top 20 memory consumers and top 20 processor
  consumers are dumped
* check cpu-percents, not absolute values
bump system image version to 3.11.15
reset error before sanity check to turn off led
trick around weird /tmp permissions ...

in some first-boot conditions
bump version of image to 3.11.16 after release
Revert "trick around weird /tmp permissions ..."

This reverts commit c39fe4dfea8340f19b973dbd252708ac56718188.