The mem stats are pretty convenient to spot leaks, except that they count
free(NULL) as 1, and the code does actually have quite a number of free(foo)
guards where foo is NULL if the object was already freed. Let's just not
count these ones so that the stats remain consistent. Now it's possible
to compare the strdup()/malloc() and free() and verify they are consistent.
Now when building with -DDEBUG_MEM_STATS, some malloc/calloc/strdup/realloc
stats are kept per file+line number and may be displayed and even reset on
the CLI using "debug dev memstats". This allows to easily track potential
leakers or abnormal usages.
This one used to be stored into debug.h but the debug tools got larger
and require a lot of other includes, which can't use BUG_ON() anymore
because of this. It does not make sense and instead this macro should
be placed into the lower includes and given its omnipresence, the best
solution is to create a new bug.h with the few surrounding macros needed
to trigger bugs and place assertions anywhere.
Another benefit is that it won't be required to add include <debug.h>
anymore to use BUG_ON, it will automatically be covered by api.h. No
less than 32 occurrences were dropped.
The FSM_PRINTF macro was dropped since not used at all anymore (probably
since 1.6 or so).
