more: use getopt_long() to parse options

more: use getopt_long() to parse options

This commit also includes fix to how initial skip lines and search are
instructed in the code.  Earlier version was pretty close impossible to make
work with getopt_long() and had minor flaw - if both initial skip lines and
search were defined at the same time the skipping did not happen.  That is
now corrected.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>