Scalar Upgrade - Compact Y Axis

# This is an Upgrade for Scalar 3D printer
This is an upgrade for Scalar M and Scalar XL 3D printers.

# Description
The current Y axis motor mount can sometime touch the heatbed when moving.
To prevent this we created a compact version of the Y Axis motor mount.
As you can see on the pictures the motor is closer to the aluminum extrusion.
Also the M3x8 screws are easier to insert in this model.
In order for you to compare the difference, we uploaded a picture with 2 parts:

-white: old model. as you can see here it's about 2 or 3mm from the bed bottom.
-grey: the compact version, the motor is closer to the extrusion, and there is more space left from the bottom of the bed.

In order for the belt to stay parallel to the bed, we also made a compact version of the idler holder.

Both parts are 9mm smaller.

Again for the belt to stay parallel to the bed we had to increase by 9mm the size of the belt holder.

All parts have the same screw position.

# Updates:
* 2016