RevF-Version-5

Corrects E1 changes (second extruder on dual extruder model) implemented in rev 3 but not built correctly into the rev 4 binary. Just to be clear about what version was broken and what fixed it, this release should work with dual extruders, while rev 4 was meant to (and by the source code here, it would have). The error was on the build and the file ultimately published on release 4.

TL;DR: Use this instead of release 4.