LM8UU X Carriage with Belt Clamps for Prusa Mendel

I was looking to upgrade the X-Carriage on my printer, and wanted a design that would serve several purposes.

1) It had to support LM8UU linear bearings.

2) It had to allow the extruder to be mounted tangentially to the x-axis, so that I could recover the print area that was currently being taken up by the extruder stepper.

3) It had to allow easy adjustment of the belt tension.

4) It had to have a place to mount an optical end-stop flag.

5) It had to provide good clearance for th