ECHOCHAR, ECHOMETA, UPARROW --> INDICATE

[KAPLAN.PA]

At least for the non-pdp10 implementations, ECHOCONTROL has been modified
to use INDICATE instead of UPARROW.  For meta characters (128-255),
INDICATE means prefix with #.  ECHOMETA coerces characters into the meta
range.  The function ECHOCHAR takes char codes with no coercion--it is called
by ECHOCONTROL and ECHOMETA after coercion to do the work.