..Parenthesis, #if, "/*" comment pair search
      C has 3 parenthesis notation (,[ and {.
      It is hard to search pair in deep nest.
      "Alt+." support it,"Alt+," search except excluded line.
      To ignore comment line,exclude those lines and use "Alt+,".
      This function support other pairing of <,> and /*,*/.
      The corresponding of same nest level of #if/#ifdef/#ifndef/#else
      /#endif/#elif is also searched.
      Move cursor on the parenthesis,# etc.,then hit key.