exa2pro/starpu-max: porting work to Maxeler DFE @ a2f330c2735532cd9f5212e05d432156a89a2dd8

Samuel Thibault 6a73a722a8 Fix destroying the task when it failed to be submitted		14 lat temu
..
invalid_blocking_calls.c	685f84fcdb Include valgrind.h in helper.h, not directly in the tests.	14 lat temu
invalid_tasks.c	6a73a722a8 Fix destroying the task when it failed to be submitted	14 lat temu
starpu_init_noworker.c	be06e1d5de check in configure.ac if unsetenv is available	14 lat temu