values > 1 will zoom in and values < 1 zoom out
Rationale: the changed orientation is more natural
from a user POV and doing it this way is also more
consistent with the calculation of the other
target_* parameters.
Compatibility: This will break *.blend files saved
with the previous version of this patch from the
last days (test period). It will *not* break any
old/migrated files: Previously, the DNA field "scale"
was only used to cache autoscale. Only with the
Stabilisator rework, "scale" becomes a first class
persistent DNA field. There is migration code to
init this field to 1.0