This allows to use EWMA_ALPHA in an #if clause, which is needed
for the next commit.
Review changes by Traumflug: made changes to comments more
complete, added rounding ("+ 500") and also adjusted Configtool
for the change.
Until this commit, the Z axis is disabled after each move and
only enabled when the Z axis will move. Now you can enable this
as a feature. Some printer axes are too heavy or have a high
pitch which are not self locking. In that case simply do nothing.
It's now off by default.
Markus Hitter
wurstnase