test-mergesort conflict with stdlib.h

On OS X 10.7.3, I get the following error attempting to build next:

    CC test-mergesort.o
In file included from test-mergesort.c:2:
./mergesort.h:4:7: error: conflicting types for 'mergesort'
void *mergesort(void *list,
      ^
/usr/include/stdlib.h:306:6: note: previous declaration is here
int      mergesort(void *, size_t, size_t,
         ^

This appears to be due to the fact that 0db71e0: "add mergesort() for linked lists" added a mergesort implementation with a different signature than a mergesort implemented by OS X's standard library.  Perhaps git could use a less generic name like 'llist_mergesort'?

~~ Brian Gernhardt