HUGE update to the way the paginator works. scr_putc() now keeps track of how many...

lines it has written, issuing the paginator prompt when it knows it needs to.  scr_getc() resets the
line count to zero.  This completely eliminates the need for individual functions to keep track of
their line count, simplifying a lot of code throughout the system.  Why didn't I do it this way 20
years ago?  TODO: use the server issued paginator prompt instead of a hardcoded string.