update german sample config, add Downconverter, keep more Attributes
adds a new Importer "Downconverter" good for copying a HD channel to a SD channel, see sample config in examples/de/nonametv.conf
adjust german sample to installation inside home directory and add all channels to the sample config
extend NonameTV::ParseXmltv to import more of the data we just exported (for Combiner, Downconverter, Timeshifter, etc.) so the Downcoverter has something to drop
use search path to find wvHtml (change utf8 to utf-8 while here to make new host happy)