Redirect the full set of heap allocation functions in the private loader

Today, the UNIX private loader only redirects these heap allocation routines:
```C
static const redirect_import_t redirect_imports[] = {
{ "calloc", (app_pc)redirect_calloc },
{ "malloc", (app_pc)redirect_malloc },
{ "free", (app_pc)redirect_free },
{ "realloc", (app_pc)redirect_realloc },
{ "strdup", (app_pc)redirect_strdup },
```

We should add more:
+ malloc_usable_size, memalign, valloc, mallinfo, mallopt, etc.
+ tcmalloc: tc_malloc, tc_free, etc.
+ __libc_malloc, __libc_free, etc.
+ OSX: malloc_zone_malloc, etc.? Or just malloc_create_zone?
+ C++ operators in case they don't just call libc malloc?