MODULATORS: Fix increment computation using a global variable

Due to a typo, the varaible "attack" was used here. This variable being
global to the test, it was actually working by chance.
The proper internal member variable "_attack" is now used.

Signed-off-by: Gama <misept.dieseneuf@gmail.com>
SCRIPTS: Remove remaining occurences of "OpenMini"

Signed-off-by: Gama <misept.dieseneuf@gmail.com>
GENERATORS: Remove printing informations during the tests

This was slowing a bit test, polluting the eventual log, and actually
not useful at all.

Signed-off-by: Gama <misept.dieseneuf@gmail.com>
TESTS: Add a function for data length computation, using it

This function gets the samples count for a given signal frequency
and expected periods count.
It allows non-integer periods count, which is quite useful for better
zerocrossing tests robustness - those were updated accordingly.
This also allow lower epsilons on these tests.
This is part of #10.

Signed-off-by: Gama <misept.dieseneuf@gmail.com>
TESTS: Better zero crossing detection

This has been improved by allowing to manually set the initial value
from which the differentiator will operate.
Also, the default initial value has been set to 1.0 since now the
zero crossing predicate is binary (e.g. 1.0 or < 1.0).
In Adsd tests, epsilons have been lowered accordingly.
This is part of #10.

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