fix no more polling when last Host entry returned an error and more
fix no more polling when last Host entry returned an error and more

- in updateDevices there was a race condition with the sand callbacks
when the last host entry was not successfully returned - then the
callback was not called and so the timeout was not set for the next
cycle … means that the adapter did not checked anything anymore
- made sure by using a pollingTimer variable that only one timeout for
the next cycle is running. there were cases where multiple timeouts
were running (high load)
- change some small coding style things on jslint advice
- commented out dead code (return before code, so was never called at
all)
- added some more error logging to get infos on errors (needs
optimization)
- also start very first „updateAll“ call by a timeout because I had
cases where it was started multiple times initially

soef/ioBroker.tr-064,soef/ioBroker.tr-064