avoid unneeded memory allocations
Add const to various variable declarations
Simplify freeing of lookup path - no need for extra elem variable
Make sure all tests call MMDB_close and free the mmdb struct
Call freeaddrinfo before returning an error
Call MMDB_free_entry_data_list() on entry_data_list struct
Make valgrind-all.pl find all the tests rather than hardcoding them by name
Add Changes note for memory allocation and const-ness