Custom drag routines error in manual and .guide.

[Hagbard-Celin]

Magellan manual and .guide claims that "custom drag routines", quote "should be ON for non-RTG (AGA,ECS)" and "for NON-graphics card users". But the code, the original changelog (look in Program/version.c in the original code release) and the v5.6 manual all say it is the other way around.