tasks now support nodes with memory within the task and account for them
when checking if a task has memory

clash+parenthesis issues in the lustre generated code)

The  parenthesis  issues  were  occuring (sometimes)  in  the  lustre
generated code,  for 'pre', '#,'  'nor', and 'current'. A  issue with
int2real and real2int was fixed too.

fix: some issues in the lustre backend wrt =current=

The rationale is to allow the use of extern types, such as int8.