extraction of subtitle (episode title) from the summary of sky-it EPG

(the regexp looks garbled because single quote can even occur in the subtitle and I don't want to introduce pcre dependency)
added some reference examples for sky-it patterns

they could be useful in the future...
extraction of part number from summary of sky-it EPG
generalized some patterns and added new cases signaled by @stan86
further pattern refinements after some extensive testing
a more robust check on the outcome of `regexec` and a more clean design