SCRIPTS: Minor changes on displayed signals when extracting test data

Various differentiated signals, zero crossings information and so on.

Signed-off-by: Gama <misept.dieseneuf@gmail.com>
SCRIPTS: Inteprolation sandbox now up to ate with last C++ implementation

This includes current reading cursor input taken into account for the
required input length.
This is analog to issue #77.

Signed-off-by: Gama <misept.dieseneuf@gmail.com>