Introduce auto fast scan functionality

At this moment auto fast scan is initiated when the box is 10 minutes in
standby. When a recording is running it will be retried once an hour as
long the box is in standby.
FastScan: simplify some code by removing a complete class
FastScan: also stop PiP when performing fastscan

This will guarentee that 'all' frontends are free to use for the FastScan
ServiceScan: Add check if session.pip really exists before deleting it
Fastscan: change auto fast scan enabled by default
FastScan: use standby screen for auto fastscan screen

So the clock will not disappear during the fastscan anymore and in
addition the power button will now also disable/abort the fastscan and
stay to put the box out of standby
Small fix for the VFD display of VUDUO2/ET8K/ET10K
Fastscan: correctly delete self.scan
FastScan: change method to del self.scan with normal fastscan

use the same method as done with auto self scan using onClose
Merge branch 'master' of git://git.code.sf.net/p/openpli/enigma2