Marlin firmware fork for MakerFarm i3v w/ auto bed level & Roxy's enhancements

[dacb]

Did some basic testing and it looks like it works. I ran through some combinations of arguments from the full blown to the original (see below) and didn't find any problems. Then I started a print and it setup fine and is working away.

E.g. G29 V4 T n3 L95 F95 R105 B105

Send: G28 X0 Y0 Z0
Recv: ok
Send: G29 V4 T n3 L95 F95 R105 B105
Recv: Roxy's Enhanced G29 Auto_Bed_Leveling Code V1.01:
Recv: Bed x: 95.00 y: 95.00 z: 7.95
Recv: Bed x: 100.00 y: 95.00 z: 7.90
Recv: Bed x: 105.00 y: 95.00 z: 7.92
Recv: Bed x: 95.00 y: 100.00 z: 7.84
Recv: Bed x: 100.00 y: 100.00 z: 7.86
Recv: Bed x: 105.00 y: 100.00 z: 7.93
Recv: Bed x: 95.00 y: 105.00 z: 7.89
Recv: Bed x: 100.00 y: 105.00 z: 7.88
Recv: Bed x: 105.00 y: 105.00 z: 7.89
Recv: Eqn coefficients: a: 0.00 b: -0.00 d: 8.09
Recv: Mean of sampled points: 7.895500
Recv: 
Recv: Bed Height Topography:
Recv:  --0.00600 --0.01700 --0.00500
Recv:  --0.05700 --0.03425 +0.03325
Recv:  +0.05875 +0.00400 +0.02325
Recv: 
Recv: planeNormal x: -0.00 y: 0.00 z: 1.00
Recv: 
Recv: 
Recv: Bed Level Correction Matrix:
Recv: 0.999998 0.000000 0.001858
Recv: 0.000007 0.999993 -0.003800
Recv: -0.001858 0.003800 0.999991
Recv: ok
Recv: echo:endstops hit:  Z:7.89

E.g. G29 V4 T n2

Send: G29 V4 T n2
Recv: Roxy's Enhanced G29 Auto_Bed_Leveling Code V1.01:
Recv: Bed x: 75.00 y: 50.00 z: 8.01
Recv: Bed x: 175.00 y: 50.00 z: 8.19
Recv: Bed x: 75.00 y: 175.00 z: 7.80
Recv: Bed x: 175.00 y: 175.00 z: 7.96
Recv: Eqn coefficients: a: 0.00 b: -0.00 d: 7.97
Recv: Mean of sampled points: 7.986500
Recv: 
Recv: Bed Height Topography:
Recv:  --0.19100 --0.03075
Recv:  +0.01850 +0.20325
Recv: 
Recv: planeNormal x: -0.00 y: 0.00 z: 1.00
Recv: 
Recv: 
Recv: Bed Level Correction Matrix:
Recv: 0.999999 0.000000 0.001725
Recv: 0.000003 0.999998 -0.001774
Recv: -0.001725 0.001774 0.999997
Recv: ok
Recv: echo:endstops hit:  Z:7.96