qpush --move: move the right patch even with comment lines
88fc876a4833 caused that we find the index of the moving patch in self.series
but look it up in self.full_series. The difference between these is that
full_series also contains comment lines, and we thus moved the wrong patch.
Use back self.full_series to find the moving patch, but take care of striping
the patch guard markers before comparing the patch name. Test cases have been
added for comments and empty lines in self.full_series, and for the case of
guarded patches.
Original patch contributed by Mads Kiilerich <mads@kiilerich.com>