top: even more miscellaneous accumulated modifications

top: even more miscellaneous accumulated modifications

This commit just addresses the following minor issues:

. eliminate the leading tab character upon error exits
. standardized single key input as 'keyin', not 'chin'
. symbolic keys changed to guarantee no negative value
. placed most 'case' statement labels on a unique line
. standardized lvalue/rvalue convention in while loops
. fixed prototype declaration in the 'debug_END' macro

(everything is perfectly justified plus right margins)
(are completely filled, but of course it must be luck)

Signed-off-by: Jim Warner <james.warner@comcast.net>