added output width/height override support to top, + misc

added output width/height override support to top, + misc

This source patch addresses the following:
 Enhancements
  . added -w command line switch, with optional argument
   ( offers complete control over width and height, in  )
   ( combination with env variables COLUMNS= and LINES= )
  . updated man document to reflect the new capability
  . reengineered Fields Management to be more flexible
    thus no longer requiring a normal sized tty
 Buglets fixed
  . forced View_SCROLL off when in 'Batch' mode
  . for narrow xterm, fixed return val in show_pmt
  . for narrow xterm, fixed cursor pos in linein
  . added a window specific end-of-line termcap ptr
   ( so clr_eol does not overwrite last printable char )
 Cosmetic changes
  . eliminated TTYGETENVYES define, incorporated as -w
  . eliminated RESIZE_LIMIT define, no longer needed
  . eliminated FIELD_CURSOR define, no longer possible
  . eliminated extra text on Fields Management screen
  . fixed miscellaneous man document typos/formatting

Signed-off-by: Jan Görig <jgorig@redhat.com>