BUG: Correction and simplification of the existing code
BUG: Correction and simplification of the existing code

-Supretion of useless global variables
-Supretion of useless initialisations
-creation of planeDef class: This class contain all the useful information for the creation of the cliping planes
-correction of the calculation of the plane equation: the plane equation that is displayed in the python consol was wrong
-simplification of the code: factorisation of some part of the code (getCoord and cliping functions) creation of new functions (getMatrix and updateSliceState)

DCBIA-OrthoLab/EasyClip-Extension,JuliaLopinto/EasyClip-Extension