Introduce new configuration option bscs-config-file which includes BSC
configuration from the given file. Both absolute and relative (to the
main config file) paths are supported.
Add 'show bscs-config' command to display current BSC configuration.
Note: it is still possible to have BSC configuration in the main
file (provided proper index number is used) and in runtime but BSC
configuration is no longer saved automatically. The management of
included configuration file is left to external tools.
Update configuration examples.
Fixes: OS#1669
Sponsored-by: On-Waves ehf
82f5ecde6a