Dymola compatibility: Displacement of statement regarding centralSecondOrder parameters in the equation section to the inside of parenthesis in the class declaration statement

- gausian propagation for transport equation
- gausien diffusion for diffusion equation
- step propagation for diffusion equation

-> Addition of ghost node to avoid boundary PDEs in the inherited modules
-> Update the HTML description and the images contained within

-> Modification to be able to transport a vectorial quantity. The transported quantity "u" has therefore the dimention u[number of dicrete node + 1, size of the quantity transported]

Correction in the size of the source term since the upstream boundary node with vertex centred scheme has no source term

Renaming the file

Change the position vector "x" prefix from input to parameters since x does not change over the time