ChannelSelection: Change behaviour number keys

Now when we are in a userbouquet the number keys do not search anymore
on alphabeth but 1 means no go to the current service when available and
2 means go to a service that is available based on the history zap data
(probably later this could be probably extended with shortcuts to context
menu options)
InfoBarGenerics: Small adjugements on timeshift
ChannelSelection: Simplify some code
Shuts downs or standby receiver when not controlled for a while

Now it can be configured that the receiver shuts down or goes to standby
(also configurable) when the receiver is turned on but not controlled for
a specific number of hours. Default this feature is currently OFF.
Merge branch 'master' of git://openpli.git.sourceforge.net/gitroot/openpli/enigma2