Also fix some reentrancy issues in the controller_load functions.

Ghost terminals still need special attention, but most blocks don't
use them and use the same malloc + initialize pattern.

-Safety blocks have some names changed
-Setpoint generator is redesigned.
 +No longer 'unitless' with 'd' as derivative, but physics names (x, v, a, j)
 +Removal of 'mirrored' code.
 +improved tracking at high speeds
 +Addition of 'precision' parameters to limit numerical noise