Remove an alignment region shifting on a click within the region

Currently, there is the following feature in the Alignment Editor: when a region is selected and a mouse click is done within the bound of the region, the region is shifted. For example, if the click is done at the left side of the region, the region is shifted to the left. If the click is don at the right, the region is shifted to the right.

This shifts and the length of the shifted region are not clear. Especially, this is very unhandy, when the region is very big.

Therefore, it is better to eliminate the feature.