Add realloc, calloc, memalign; centralize hook setup, add chunksize
* copy some macros from glibc
* centralize HOOK macro
* add realloc
* add calloc
* add memalign
* add posix_memalign
* add valloc
* add pvalloc
* enable chunksize tracing
Reviewed-by: Carlos O'Donell <carlos@redhat.com>.