screws_tilt_adjust: Add new screws_tilt_adjust tool (#1367)

Signed-off-by: Rui Caridade <rui.mcbc@gmail.com>

config/example-delta.cfg

@@ -126,6 +126,9 @@ radius: 50
 #samples: 1
 #   The number of times to probe each point.  The probed z-values will
 #   be averaged. The default is to probe 1 time.
+#samples_result: average
+#   One can choose median or average between probes samples
+#   The default is average.
 #sample_retract_dist: 2.0
 #   The distance (in mm) to retract between each sample if sampling
 #   more than once. The default is 2mm.