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