These macros take the place of the common 4 or 5 line blocks of code we had
in most places that called malloc or calloc. This should reduce some code
duplication and make memory allocation more standard in libalpm.
Highlights:
* Note that the MALLOC macro actually uses calloc, this is just for safety
so that memory is initialized to 0. This can be easily changed in one
place.
* One malloc call was completely eliminated- it made more sense to do it
on the stack.
* The use of RET_ERR in public functions (mainly the alpm_*_new functions)
was standardized, this makes sense so pm_errno is set.
Signed-off-by: Dan McGee <dan@archlinux.org>
