Transferred the variable creation to the new subroutine call.
Now we do not overload the assignment operator for clarity in code.
The default options of the assign, associate routines are now strictly following
regular fortran conventions:
 - a = b overwrites a, no matter the previous state
 - a => b looses the memory placement in the previous state (possible memory leak)
It is thus now up to the programmer to confine the memory.