Draft:fortran interface fix

This merge request adds some missing fortran interfaces as well as correct the name of fstarpu_arbiter_destroy.

To be discussed : It also adds a new subroutine to create "buffered" synchronization tasks fstarpu_task_create_sync : its implementation is a little hacky as it is only setting the 0-th buffer of a task to a handle given in argument as well as the codelet of the task. The codelet handed out by the user is expected to set where to STARPU_NOWHERE (otherwise the codelet executes). starpu_create_sync_task is not fitted for our purpose because we require a synchronization task who accesses a handle to leverage sequential consistency. This "fortran-sync-task" is a synchronization "in the past" as it expects tasks to depend on it (it is actually synchronizing through end_dep routines). The use case comes from qr_mumps and the need to detect collective communications (cf. nmad-coop-mcast)