Remove xmalloc, xcalloc, xrealloc and xstrdup from utils.h and revert calls
to the normal malloc, calloc, realloc, strdup. Add new files malloc_wrap.[ch]
with the wrapper functions. malloc_wrap.h #defines malloc etc. to the
wrapper, but only if USE_MALLOC_WRAPPERS has been defined.
Put #include "malloc_wrap.h" in any file that uses *alloc or strdup. This
is also in a #ifdef USE_MALLOC_WRAPPERS ... #endif block to make using the
wrappers optional. Add -DUSE_MALLOC_WRAPPERS into the makefile so they
should normally get added.
This is an improvement on the previous method as we now don't need to
worry about stray function calls that were not changed to the wrapped version
and the code will still work even if the wrapping is disabled.
Other possible methods of doing this are using malloc_hook (glibc-specific),
adding -include malloc_wrap.h to the gcc command-line (somewhat
gcc-specific) or making our own malloc function and using dlopen (scary).
This way is probably the most portable.
This move is dangerous as SAM printing is very complex, but it will benefit in
the long run. The planned change will reduce the redundancy, improves clarity
and most importantly makes it much easier to output multiple primary hits in an
optional tag.