Test, fix, develop genserkins need help

Seem there is no test for genserkins, this module has many bugs and unnecessary functions.

When i run Puma560 i found out :
+ gomath library has some errors ( i reported here : github.com/LinuxCNC/linuxcnc/issues/389 )
+ Whenever i control robot via MDI mode (Manual mode is ok), the terminal will show : "ERR kI - compute_jinv (joints: 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000), (iterations=0) " but the linuxcnc is still running.

i found out the function go_matrix_inv() cause this error but donnt know exactly what wrong because everything normal when i use Manual mode or test genserkins standalone