create a init_globals that can be runned several times, especially for unitary test (and test for dissipation)

The problem occurs for test_disk.f90. 

To make a long story short, some test dissipate the disk, and then modify some 
global parameters, and for consecutive tests, theses globals parameters 
complicate everything and make everything false. 

But since init_globals try to execute only once, I can't execute init_globals 
several times so far. I need to find a way to do this. One way is to define 
"first_call" as a global parameter of "disk.f90" and modify it manually in the 
tests to be allowed to force init_global to run several times. 

But in addition, I need to test in init_globals before allocate, because in 
this case, the allocate will fail, because the values are already allocated.

Original issue reported on code.google.com by aut...@gmail.com on 8 Oct 2012 at 5:21

EmelineBolmont / mercury-90

create a init_globals that can be runned several times, especially for unitary test (and test for dissipation) #23