elfutils:
- Fix MASTER_SITES URL.
- Install included elf.h, until base elf.h can be updated to include
Elf_Section and Elf_auxv_t.
- Patch installed libelf.h to use off_t instead of loff_t. Perhaps base should
add loff_t as an alias for compatibility.
Reviewed by: portlint
Sponsored by: EMC / Isilon Storage Division