Type detection based on SysFs.

Implementation of GetTypeFromSysfs was inspired by implementation of
get_iface_type which comes from
- /etc/sysconfig/network/scripts/functions
- sysconfig.rpm version 0.80.5
Integrated GetTypeFromSysfs into common type detection workflow.

Conflicts:
	library/network/src/NetworkInterfaces.ycp
Adapted testsuite.

Supresses an output generated by shell execution in GetTypeFromSysfs
Newly imported FileUtils emits more log messages as well.
Updated changelog.